 <p>Always make sure you've loaded the html first before actually calling the selectable function.</p> <pre><code>$(function() { var html = ''; html += '&lt;ul id="selectable"&gt;'; html += '&lt;li&gt;1&lt;/li&gt;'; html += '&lt;li&gt;2&lt;/li&gt;'; html += '&lt;li&gt;3&lt;/li&gt;'; html += '&lt;/ul&gt;'; $('#dialog').html(html).dialog(); $('#selectable').selectable(); }); </code></pre> <p>here's a <a href="http://jsfiddle.net/N4spA/" rel="nofollow">jsfiddle example</a></p>