Question

This code looks at if dropdownlist with ‘townid’ has an option of Central and then puts Central after the first option at all dropdownlists.

 var central = $('#townid option:contains("Central")');
   if(central){
     central.insertAfter('select option:first-child');
   }

My problem is that:

How can I add it just after dropdownlist that has id of townid? I mean something like:

 var central = $('#townid option:contains("Central")');
   if(central){
     central.insertAfter('#townid select option:first-child');
   }

For example:

 <select id=townid>
    <option value="5000">AL</option>
    <option value="5001">NY</option>
    <option value="5002">LA</option>
    <option value="5003">NY</option>
    <option value="5204">Central</option>
    <option value="5024">FA</option>
 </select>

 <select id="someid">
    <option value="3002">Brooklyn</option>
    <option value="6001">Manhattan</option>
 </select>

After that process they should be seem like:

 <select id=townid>
    <option value="5000">AL</option>
    <option value="5204">Central</option>
    <option value="5001">NY</option>
    <option value="5002">LA</option>
    <option value="5003">NY</option>
    <option value="5024">FA</option>
 </select>

 <select id="someid">
    <option value="3002">Brooklyn</option>
    <option value="6001">Manhattan</option>
 </select>

Answer 1

You just messed up the selector, because #townid IS the select tag.

 var central = $('#townid option:contains("Central")');
   if(central.length === 1){
     central.insertAfter('#townid option:first-child');
   }