A drop-down box for colors and want to add new colors to it, as well as remove options from it.

<label for="colors">Colors</label>
<select id="colors" multiple="multiple">
<option>Black</options>
<option>Blue</options>
<option>Brown</options>
</select>
<button id="remove">Remove Selected Color(s)</button>
<label for="newColorName">New Color Name</label>
<input id="newColorName" type="text" />
<label for="newColorValue">New Color Value</label>
<input id="newColorValue" type="text" />
<button id="add">Add New Color</button>

To add a new option to the drop-down box, use the .appendTo() method:

// find the "Add New Color" button
$('#add').click(function(event){
event.preventDefault();
var optionName = $('#newColorName').val();
var optionValue = $('#newColorValue').val();
$('<option/>').attr('value',optionValue).text(optionName).appendTo('#colors');
});

To remove an option, use the .remove() method:

// find the "Remove Selected Color(s)" button
$('#remove').click(function(event){
event.preventDefault();
var $select = $('#colors');
$('option:selected',$select).remove();
});