SO - 17652618

by Arun P Johny

HTML

<input type="checkbox" />
<select id="selectlist" name="selectproduct" >
    <option value=""> --- Select product  --- </option>
    <option value="1">Product 1</option>
    <option value="2">Product 2</option>
    <option value="3">Product 3</option>
    <option value="4">Product 4</option>
</select>

JavaScript

var sel = $('#selectlist');
var opts = sel.find('option');

$(':checkbox').click(function(){
    sel.empty().append(this.checked ? opts : opts.filter('[value!=4]'));
}).click()