jQuery Moving Items from one list to another

$(document).ready(function() {
    $('#add').click(function() {
        return !$('#select1 option:selected').appendTo('#select2');
    });
    $('#remove').click(function() {
        return !$('#select2 option:selected').appendTo('#select1');
    });
});

<div>
Group 1:
    <select multiple id="select1">
        <option value="1">Ajax</option>
        <option value="2">jQuery</option>
        <option value="3">JavaScript</option>
        <option value="4">Moo Tools</option>
        <option value="5">Prototype</option>
        <option value="6">Dojo</option>
    </select>
    <a href="#" id="add">add &gt;&gt;</a> </div>
<div>
Group 2:
    <select multiple id="select2">
        <option value="7">ASP .NET</option>
        <option value="8">C#</option>
        <option value="9">VB .NET</option>
        <option value="10">Java</option>
        <option value="11">PHP</option>
        <option value="12">Python</option>
    </select>
    <a href="#" id="remove">&lt;&lt; remove</a>
</div>

Originally posted by Jeremy Martin