Chosen is a JavaScript plugin that makes long, unwieldy select boxes much more user-friendly. It is currently available in both jQuery and Prototype flavors. 
          Project page on GitHub 
          Standard Select 
          
            
              Turns This 
              
                  
                United States  
                United Kingdom  
                Afghanistan  
                Albania  
                Algeria  
                American Samoa  
                Andorra  
                Angola  
                Anguilla  
                Antarctica  
                Antigua and Barbuda  
                Argentina  
                Armenia  
                Aruba  
                Australia  
                Austria  
                Azerbaijan  
                Bahamas  
                Bahrain  
                Bangladesh  
                Barbados  
                Belarus  
                Belgium  
                Belize  
                Benin  
                Bermuda  
                Bhutan  
                Bolivia  
                Bosnia and Herzegovina  
                Botswana  
                Bouvet Island  
                Brazil  
                British Indian Ocean Territory  
                Brunei Darussalam  
                Bulgaria  
                Burkina Faso  
                Burundi  
                Cambodia  
                Cameroon  
                Canada  
                Cape Verde  
                Cayman Islands  
                Central African Republic  
                Chad  
                Chile  
                China  
                Christmas Island  
                Cocos (Keeling) Islands  
                Colombia  
                Comoros  
                Congo  
                Congo, The Democratic Republic of The  
                Cook Islands  
                Costa Rica  
                Cote D'ivoire  
                Croatia  
                Cuba  
                Cyprus  
                Czech Republic  
                Denmark  
                Djibouti  
                Dominica  
                Dominican Republic  
                Ecuador  
                Egypt  
                El Salvador  
                Equatorial Guinea  
                Eritrea  
                Estonia  
                Ethiopia  
                Falkland Islands (Malvinas)  
                Faroe Islands  
                Fiji  
                Finland  
                France  
                French Guiana  
                French Polynesia  
                French Southern Territories  
                Gabon  
                Gambia  
                Georgia  
                Germany  
                Ghana  
                Gibraltar  
                Greece  
                Greenland  
                Grenada  
                Guadeloupe  
                Guam  
                Guatemala  
                Guinea  
                Guinea-bissau  
                Guyana  
                Haiti  
                Heard Island and Mcdonald Islands  
                Holy See (Vatican City State)  
                Honduras  
                Hong Kong  
                Hungary  
                Iceland  
                India  
                Indonesia  
                Iran, Islamic Republic of  
                Iraq  
                Ireland  
                Israel  
                Italy  
                Jamaica  
                Japan  
                Jordan  
                Kazakhstan  
                Kenya  
                Kiribati  
                Korea, Democratic People's Republic of  
                Korea, Republic of  
                Kuwait  
                Kyrgyzstan  
                Lao People's Democratic Republic  
                Latvia  
                Lebanon  
                Lesotho  
                Liberia  
                Libyan Arab Jamahiriya  
                Liechtenstein  
                Lithuania  
                Luxembourg  
                Macao  
                Macedonia, The Former Yugoslav Republic of  
                Madagascar  
                Malawi  
                Malaysia  
                Maldives  
                Mali  
                Malta  
                Marshall Islands  
                Martinique  
                Mauritania  
                Mauritius  
                Mayotte  
                Mexico  
                Micronesia, Federated States of  
                Moldova, Republic of  
                Monaco  
                Mongolia  
                Montenegro 
                Montserrat  
                Morocco  
                Mozambique  
                Myanmar  
                Namibia  
                Nauru  
                Nepal  
                Netherlands  
                Netherlands Antilles  
                New Caledonia  
                New Zealand  
                Nicaragua  
                Niger  
                Nigeria  
                Niue  
                Norfolk Island  
                Northern Mariana Islands  
                Norway  
                Oman  
                Pakistan  
                Palau  
                Palestinian Territory, Occupied  
                Panama  
                Papua New Guinea  
                Paraguay  
                Peru  
                Philippines  
                Pitcairn  
                Poland  
                Portugal  
                Puerto Rico  
                Qatar  
                Reunion  
                Romania  
                Russian Federation  
                Rwanda  
                Saint Helena  
                Saint Kitts and Nevis  
                Saint Lucia  
                Saint Pierre and Miquelon  
                Saint Vincent and The Grenadines  
                Samoa  
                San Marino  
                Sao Tome and Principe  
                Saudi Arabia  
                Senegal  
                Serbia  
                Seychelles  
                Sierra Leone  
                Singapore  
                Slovakia  
                Slovenia  
                Solomon Islands  
                Somalia  
                South Africa  
                South Georgia and The South Sandwich Islands  
                South Sudan  
                Spain  
                Sri Lanka  
                Sudan  
                Suriname  
                Svalbard and Jan Mayen  
                Swaziland  
                Sweden  
                Switzerland  
                Syrian Arab Republic  
                Taiwan, Republic of China  
                Tajikistan  
                Tanzania, United Republic of  
                Thailand  
                Timor-leste  
                Togo  
                Tokelau  
                Tonga  
                Trinidad and Tobago  
                Tunisia  
                Turkey  
                Turkmenistan  
                Turks and Caicos Islands  
                Tuvalu  
                Uganda  
                Ukraine  
                United Arab Emirates  
                United Kingdom  
                United States  
                United States Minor Outlying Islands  
                Uruguay  
                Uzbekistan  
                Vanuatu  
                Venezuela  
                Viet Nam  
                Virgin Islands, British  
                Virgin Islands, U.S.  
                Wallis and Futuna  
                Western Sahara  
                Yemen  
                Zambia  
                Zimbabwe 
               
            
            
              Into This         
              
                  
                United States  
                United Kingdom  
                Afghanistan  
                Albania  
                Algeria  
                American Samoa  
                Andorra  
                Angola  
                Anguilla  
                Antarctica  
                Antigua and Barbuda  
                Argentina  
                Armenia  
                Aruba  
                Australia  
                Austria  
                Azerbaijan  
                Bahamas  
                Bahrain  
                Bangladesh  
                Barbados  
                Belarus  
                Belgium  
                Belize  
                Benin  
                Bermuda  
                Bhutan  
                Bolivia  
                Bosnia and Herzegovina  
                Botswana  
                Bouvet Island  
                Brazil  
                British Indian Ocean Territory  
                Brunei Darussalam  
                Bulgaria  
                Burkina Faso  
                Burundi  
                Cambodia  
                Cameroon  
                Canada  
                Cape Verde  
                Cayman Islands  
                Central African Republic  
                Chad  
                Chile  
                China  
                Christmas Island  
                Cocos (Keeling) Islands  
                Colombia  
                Comoros  
                Congo  
                Congo, The Democratic Republic of The  
                Cook Islands  
                Costa Rica  
                Cote D'ivoire  
                Croatia  
                Cuba  
                Cyprus  
                Czech Republic  
                Denmark  
                Djibouti  
                Dominica  
                Dominican Republic  
                Ecuador  
                Egypt  
                El Salvador  
                Equatorial Guinea  
                Eritrea  
                Estonia  
                Ethiopia  
                Falkland Islands (Malvinas)  
                Faroe Islands  
                Fiji  
                Finland  
                France  
                French Guiana  
                French Polynesia  
                French Southern Territories  
                Gabon  
                Gambia  
                Georgia  
                Germany  
                Ghana  
                Gibraltar  
                Greece  
                Greenland  
                Grenada  
                Guadeloupe  
                Guam  
                Guatemala  
                Guinea  
                Guinea-bissau  
                Guyana  
                Haiti  
                Heard Island and Mcdonald Islands  
                Holy See (Vatican City State)  
                Honduras  
                Hong Kong  
                Hungary  
                Iceland  
                India  
                Indonesia  
                Iran, Islamic Republic of  
                Iraq  
                Ireland  
                Israel  
                Italy  
                Jamaica  
                Japan  
                Jordan  
                Kazakhstan  
                Kenya  
                Kiribati  
                Korea, Democratic People's Republic of  
                Korea, Republic of  
                Kuwait  
                Kyrgyzstan  
                Lao People's Democratic Republic  
                Latvia  
                Lebanon  
                Lesotho  
                Liberia  
                Libyan Arab Jamahiriya  
                Liechtenstein  
                Lithuania  
                Luxembourg  
                Macao  
                Macedonia, The Former Yugoslav Republic of  
                Madagascar  
                Malawi  
                Malaysia  
                Maldives  
                Mali  
                Malta  
                Marshall Islands  
                Martinique  
                Mauritania  
                Mauritius  
                Mayotte  
                Mexico  
                Micronesia, Federated States of  
                Moldova, Republic of  
                Monaco  
                Mongolia  
                Montenegro 
                Montserrat  
                Morocco  
                Mozambique  
                Myanmar  
                Namibia  
                Nauru  
                Nepal  
                Netherlands  
                Netherlands Antilles  
                New Caledonia  
                New Zealand  
                Nicaragua  
                Niger  
                Nigeria  
                Niue  
                Norfolk Island  
                Northern Mariana Islands  
                Norway  
                Oman  
                Pakistan  
                Palau  
                Palestinian Territory, Occupied  
                Panama  
                Papua New Guinea  
                Paraguay  
                Peru  
                Philippines  
                Pitcairn  
                Poland  
                Portugal  
                Puerto Rico  
                Qatar  
                Reunion  
                Romania  
                Russian Federation  
                Rwanda  
                Saint Helena  
                Saint Kitts and Nevis  
                Saint Lucia  
                Saint Pierre and Miquelon  
                Saint Vincent and The Grenadines  
                Samoa  
                San Marino  
                Sao Tome and Principe  
                Saudi Arabia  
                Senegal  
                Serbia  
                Seychelles  
                Sierra Leone  
                Singapore  
                Slovakia  
                Slovenia  
                Solomon Islands  
                Somalia  
                South Africa  
                South Georgia and The South Sandwich Islands  
                South Sudan  
                Spain  
                Sri Lanka  
                Sudan  
                Suriname  
                Svalbard and Jan Mayen  
                Swaziland  
                Sweden  
                Switzerland  
                Syrian Arab Republic  
                Taiwan, Republic of China  
                Tajikistan  
                Tanzania, United Republic of  
                Thailand  
                Timor-leste  
                Togo  
                Tokelau  
                Tonga  
                Trinidad and Tobago  
                Tunisia  
                Turkey  
                Turkmenistan  
                Turks and Caicos Islands  
                Tuvalu  
                Uganda  
                Ukraine  
                United Arab Emirates  
                United Kingdom  
                United States  
                United States Minor Outlying Islands  
                Uruguay  
                Uzbekistan  
                Vanuatu  
                Venezuela  
                Viet Nam  
                Virgin Islands, British  
                Virgin Islands, U.S.  
                Wallis and Futuna  
                Western Sahara  
                Yemen  
                Zambia  
                Zimbabwe 
               
            
           
          Multiple Select 
          
            
              Turns This 
              
                United States  
                United Kingdom  
                Afghanistan  
                Albania  
                Algeria  
                American Samoa  
                Andorra  
                Angola  
                Anguilla  
                Antarctica  
                Antigua and Barbuda  
                Argentina  
                Armenia  
                Aruba  
                Australia  
                Austria  
                Azerbaijan  
                Bahamas  
                Bahrain  
                Bangladesh  
                Barbados  
                Belarus  
                Belgium  
                Belize  
                Benin  
                Bermuda  
                Bhutan  
                Bolivia  
                Bosnia and Herzegovina  
                Botswana  
                Bouvet Island  
                Brazil  
                British Indian Ocean Territory  
                Brunei Darussalam  
                Bulgaria  
                Burkina Faso  
                Burundi  
                Cambodia  
                Cameroon  
                Canada  
                Cape Verde  
                Cayman Islands  
                Central African Republic  
                Chad  
                Chile  
                China  
                Christmas Island  
                Cocos (Keeling) Islands  
                Colombia  
                Comoros  
                Congo  
                Congo, The Democratic Republic of The  
                Cook Islands  
                Costa Rica  
                Cote D'ivoire  
                Croatia  
                Cuba  
                Cyprus  
                Czech Republic  
                Denmark  
                Djibouti  
                Dominica  
                Dominican Republic  
                Ecuador  
                Egypt  
                El Salvador  
                Equatorial Guinea  
                Eritrea  
                Estonia  
                Ethiopia  
                Falkland Islands (Malvinas)  
                Faroe Islands  
                Fiji  
                Finland  
                France  
                French Guiana  
                French Polynesia  
                French Southern Territories  
                Gabon  
                Gambia  
                Georgia  
                Germany  
                Ghana  
                Gibraltar  
                Greece  
                Greenland  
                Grenada  
                Guadeloupe  
                Guam  
                Guatemala  
                Guinea  
                Guinea-bissau  
                Guyana  
                Haiti  
                Heard Island and Mcdonald Islands  
                Holy See (Vatican City State)  
                Honduras  
                Hong Kong  
                Hungary  
                Iceland  
                India  
                Indonesia  
                Iran, Islamic Republic of  
                Iraq  
                Ireland  
                Israel  
                Italy  
                Jamaica  
                Japan  
                Jordan  
                Kazakhstan  
                Kenya  
                Kiribati  
                Korea, Democratic People's Republic of  
                Korea, Republic of  
                Kuwait  
                Kyrgyzstan  
                Lao People's Democratic Republic  
                Latvia  
                Lebanon  
                Lesotho  
                Liberia  
                Libyan Arab Jamahiriya  
                Liechtenstein  
                Lithuania  
                Luxembourg  
                Macao  
                Macedonia, The Former Yugoslav Republic of  
                Madagascar  
                Malawi  
                Malaysia  
                Maldives  
                Mali  
                Malta  
                Marshall Islands  
                Martinique  
                Mauritania  
                Mauritius  
                Mayotte  
                Mexico  
                Micronesia, Federated States of  
                Moldova, Republic of  
                Monaco  
                Mongolia  
                Montenegro 
                Montserrat  
                Morocco  
                Mozambique  
                Myanmar  
                Namibia  
                Nauru  
                Nepal  
                Netherlands  
                Netherlands Antilles  
                New Caledonia  
                New Zealand  
                Nicaragua  
                Niger  
                Nigeria  
                Niue  
                Norfolk Island  
                Northern Mariana Islands  
                Norway  
                Oman  
                Pakistan  
                Palau  
                Palestinian Territory, Occupied  
                Panama  
                Papua New Guinea  
                Paraguay  
                Peru  
                Philippines  
                Pitcairn  
                Poland  
                Portugal  
                Puerto Rico  
                Qatar  
                Reunion  
                Romania  
                Russian Federation  
                Rwanda  
                Saint Helena  
                Saint Kitts and Nevis  
                Saint Lucia  
                Saint Pierre and Miquelon  
                Saint Vincent and The Grenadines  
                Samoa  
                San Marino  
                Sao Tome and Principe  
                Saudi Arabia  
                Senegal  
                Serbia  
                Seychelles  
                Sierra Leone  
                Singapore  
                Slovakia  
                Slovenia  
                Solomon Islands  
                Somalia  
                South Africa  
                South Georgia and The South Sandwich Islands  
                South Sudan  
                Spain  
                Sri Lanka  
                Sudan  
                Suriname  
                Svalbard and Jan Mayen  
                Swaziland  
                Sweden  
                Switzerland  
                Syrian Arab Republic  
                Taiwan, Republic of China  
                Tajikistan  
                Tanzania, United Republic of  
                Thailand  
                Timor-leste  
                Togo  
                Tokelau  
                Tonga  
                Trinidad and Tobago  
                Tunisia  
                Turkey  
                Turkmenistan  
                Turks and Caicos Islands  
                Tuvalu  
                Uganda  
                Ukraine  
                United Arab Emirates  
                United Kingdom  
                United States  
                United States Minor Outlying Islands  
                Uruguay  
                Uzbekistan  
                Vanuatu  
                Venezuela  
                Viet Nam  
                Virgin Islands, British  
                Virgin Islands, U.S.  
                Wallis and Futuna  
                Western Sahara  
                Yemen  
                Zambia  
                Zimbabwe 
               
            
            
              Into This         
              
                  
                United States  
                United Kingdom  
                Afghanistan  
                Albania  
                Algeria  
                American Samoa  
                Andorra  
                Angola  
                Anguilla  
                Antarctica  
                Antigua and Barbuda  
                Argentina  
                Armenia  
                Aruba  
                Australia  
                Austria  
                Azerbaijan  
                Bahamas  
                Bahrain  
                Bangladesh  
                Barbados  
                Belarus  
                Belgium  
                Belize  
                Benin  
                Bermuda  
                Bhutan  
                Bolivia  
                Bosnia and Herzegovina  
                Botswana  
                Bouvet Island  
                Brazil  
                British Indian Ocean Territory  
                Brunei Darussalam  
                Bulgaria  
                Burkina Faso  
                Burundi  
                Cambodia  
                Cameroon  
                Canada  
                Cape Verde  
                Cayman Islands  
                Central African Republic  
                Chad  
                Chile  
                China  
                Christmas Island  
                Cocos (Keeling) Islands  
                Colombia  
                Comoros  
                Congo  
                Congo, The Democratic Republic of The  
                Cook Islands  
                Costa Rica  
                Cote D'ivoire  
                Croatia  
                Cuba  
                Cyprus  
                Czech Republic  
                Denmark  
                Djibouti  
                Dominica  
                Dominican Republic  
                Ecuador  
                Egypt  
                El Salvador  
                Equatorial Guinea  
                Eritrea  
                Estonia  
                Ethiopia  
                Falkland Islands (Malvinas)  
                Faroe Islands  
                Fiji  
                Finland  
                France  
                French Guiana  
                French Polynesia  
                French Southern Territories  
                Gabon  
                Gambia  
                Georgia  
                Germany  
                Ghana  
                Gibraltar  
                Greece  
                Greenland  
                Grenada  
                Guadeloupe  
                Guam  
                Guatemala  
                Guinea  
                Guinea-bissau  
                Guyana  
                Haiti  
                Heard Island and Mcdonald Islands  
                Holy See (Vatican City State)  
                Honduras  
                Hong Kong  
                Hungary  
                Iceland  
                India  
                Indonesia  
                Iran, Islamic Republic of  
                Iraq  
                Ireland  
                Israel  
                Italy  
                Jamaica  
                Japan  
                Jordan  
                Kazakhstan  
                Kenya  
                Kiribati  
                Korea, Democratic People's Republic of  
                Korea, Republic of  
                Kuwait  
                Kyrgyzstan  
                Lao People's Democratic Republic  
                Latvia  
                Lebanon  
                Lesotho  
                Liberia  
                Libyan Arab Jamahiriya  
                Liechtenstein  
                Lithuania  
                Luxembourg  
                Macao  
                Macedonia, The Former Yugoslav Republic of  
                Madagascar  
                Malawi  
                Malaysia  
                Maldives  
                Mali  
                Malta  
                Marshall Islands  
                Martinique  
                Mauritania  
                Mauritius  
                Mayotte  
                Mexico  
                Micronesia, Federated States of  
                Moldova, Republic of  
                Monaco  
                Mongolia  
                Montenegro 
                Montserrat  
                Morocco  
                Mozambique  
                Myanmar  
                Namibia  
                Nauru  
                Nepal  
                Netherlands  
                Netherlands Antilles  
                New Caledonia  
                New Zealand  
                Nicaragua  
                Niger  
                Nigeria  
                Niue  
                Norfolk Island  
                Northern Mariana Islands  
                Norway  
                Oman  
                Pakistan  
                Palau  
                Palestinian Territory, Occupied  
                Panama  
                Papua New Guinea  
                Paraguay  
                Peru  
                Philippines  
                Pitcairn  
                Poland  
                Portugal  
                Puerto Rico  
                Qatar  
                Reunion  
                Romania  
                Russian Federation  
                Rwanda  
                Saint Helena  
                Saint Kitts and Nevis  
                Saint Lucia  
                Saint Pierre and Miquelon  
                Saint Vincent and The Grenadines  
                Samoa  
                San Marino  
                Sao Tome and Principe  
                Saudi Arabia  
                Senegal  
                Serbia  
                Seychelles  
                Sierra Leone  
                Singapore  
                Slovakia  
                Slovenia  
                Solomon Islands  
                Somalia  
                South Africa  
                South Georgia and The South Sandwich Islands  
                South Sudan  
                Spain  
                Sri Lanka  
                Sudan  
                Suriname  
                Svalbard and Jan Mayen  
                Swaziland  
                Sweden  
                Switzerland  
                Syrian Arab Republic  
                Taiwan, Republic of China  
                Tajikistan  
                Tanzania, United Republic of  
                Thailand  
                Timor-leste  
                Togo  
                Tokelau  
                Tonga  
                Trinidad and Tobago  
                Tunisia  
                Turkey  
                Turkmenistan  
                Turks and Caicos Islands  
                Tuvalu  
                Uganda  
                Ukraine  
                United Arab Emirates  
                United Kingdom  
                United States  
                United States Minor Outlying Islands  
                Uruguay  
                Uzbekistan  
                Vanuatu  
                Venezuela  
                Viet Nam  
                Virgin Islands, British  
                Virgin Islands, U.S.  
                Wallis and Futuna  
                Western Sahara  
                Yemen  
                Zambia  
                Zimbabwe 
               
            
           
          <optgroup> Support 
          
            
              Single Select with Groups 
              
                 
                
                  Dallas Cowboys 
                  New York Giants 
                  Philadelphia Eagles 
                  Washington Redskins 
                
                
                  Chicago Bears 
                  Detroit Lions 
                  Green Bay Packers 
                  Minnesota Vikings 
                 
                
                  Atlanta Falcons 
                  Carolina Panthers 
                  New Orleans Saints 
                  Tampa Bay Buccaneers 
                 
                
                  Arizona Cardinals 
                  St. Louis Rams 
                  San Francisco 49ers 
                  Seattle Seahawks 
                 
                
                  Buffalo Bills 
                  Miami Dolphins 
                  New England Patriots 
                  New York Jets 
                 
                
                  Baltimore Ravens 
                  Cincinnati Bengals 
                  Cleveland Browns 
                  Pittsburgh Steelers 
                 
                
                  Houston Texans 
                  Indianapolis Colts 
                  Jacksonville Jaguars 
                  Tennessee Titans 
                 
                
                  Denver Broncos 
                  Kansas City Chiefs 
                  Oakland Raiders 
                  San Diego Chargers 
                 
                 
            
            
              Multiple Select with Groups 
              
                 
                
                  Dallas Cowboys 
                  New York Giants 
                  Philadelphia Eagles 
                  Washington Redskins 
                
                
                  Chicago Bears 
                  Detroit Lions 
                  Green Bay Packers 
                  Minnesota Vikings 
                 
                
                  Atlanta Falcons 
                  Carolina Panthers 
                  New Orleans Saints 
                  Tampa Bay Buccaneers 
                 
                
                  Arizona Cardinals 
                  St. Louis Rams 
                  San Francisco 49ers 
                  Seattle Seahawks 
                 
                
                  Buffalo Bills 
                  Miami Dolphins 
                  New England Patriots 
                  New York Jets 
                 
                
                  Baltimore Ravens 
                  Cincinnati Bengals 
                  Cleveland Browns 
                  Pittsburgh Steelers 
                 
                
                  Houston Texans 
                  Indianapolis Colts 
                  Jacksonville Jaguars 
                  Tennessee Titans 
                 
                
                  Denver Broncos 
                  Kansas City Chiefs 
                  Oakland Raiders 
                  San Diego Chargers 
                 
                 
            
           
          Selected and Disabled Support 
          
            Chosen automatically highlights selected options and removes disabled options.
            
              Single Select 
              
                 
                American Black Bear 
                Asiatic Black Bear 
                Brown Bear 
                Giant Panda 
                Sloth Bear 
                Sun Bear 
                Polar Bear 
                Spectacled Bear 
               
            
            
              Multiple Select 
              
                 
                American Black Bear 
                Asiatic Black Bear 
                Brown Bear 
                Giant Panda 
                Sloth Bear 
                Sun Bear 
                Polar Bear 
                Spectacled Bear 
               
            
           
          Default Text Support 
          
            Chosen automatically sets the default field text ("Choose a country...") by reading the select element's data-placeholder value. If no data-placeholder value is present, it will default to "Select Some Option" or "Select Some Options" depending on whether the select is single or multiple. You can change these elements in the plugin js file as you see fit.
            <select data-placeholder="Choose a country..." style="width:350px;" multiple class="chzn-select"">
            Note:  on single selects, the first element is assumed to be selected by the browser. To take advantage of the default text support, you will need to include a blank option as the first element of your select list.
           
          
          Change / Update Events 
          
            
              
                Form Field Change 
                When working with form fields, you often want to perform some behavior after a value has been selected or deselected. Whenever a user selects a field in Chosen, it triggers a "change" event* on the original form field. That let's you do something like this:
                $("#form_field").chosen().change( … );
                Note:  Prototype doesn't offer support for triggering standard browser events. Event.simulate  is required to trigger the change event when using the Prototype version.
               
              
                Updating Chosen Dynamically 
                If you need to update the options in your select field and want Chosen to pick up the changes, you'll need to trigger the "liszt:updated" event on the field. Chosen will re-build itself based on the updated content.
                
                  jQuery Version:  $("#form_field").trigger("liszt:updated"); 
                  Prototype Version:  Event.fire($("form_field"), "liszt:updated"); 
                 
               
             
           
          Why use Chosen? 
          
            
              User Friendly 
              Instead of forcing your users to scroll through a giant list of items, they can just start typing the name of the item they were looking for. Non-matching entries are removed from view and choices can be selected using enter or mouse click.
             
            
              Progressive Enhancement 
              Because chosen replaces normal html select fields, you don't need to do anything special to make it work for browsers without JavaScript. You don't need to do anything special on the back end to handle the data either -- the form field still gets submitted as normal.
             
            
              Painless Setup 
              Add Chosen's files to your app and trigger the plugin (see Setup below). Chosen automatically respects optgroups, selected state, the multiple attribute and browser tab order. You don't need to do anything else except customize the style as you see fit.
             
           
          Setup 
          Using Chosen is easy as can be.
          
            Download the plugin  and copy the related files to your app. 
            Activate the plugin:
              
                jQuery Version:  Call the chosen plugin - $(".chzn-select").chosen() 
                Prototype Version:  Add the class chzn-select  to appropriate select boxes. 
               
            
             Disco . 
           
          
          Notable Forks 
          
          FAQs 
          
            
              Something doesn't work. Can you fix it? 
              Yes! Please report all issues using the GitHub issue tracking tool . Please include the plugin version (jQuery or Prototype), browser and OS. The more information provided, the easier it is to fix a problem.
             
            
              What browsers are supported? 
              All modern browsers are support (Firefox, Chrome, Safari and IE9). Legacy support for IE8 is also enabled.