Test Case Boilerplate
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HTML
<script src="http://code.jquery.com/ui/jquery-ui-git.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/ui/jquery-ui-git.css">
<ul>
<li><img src="1.jpg" /></li>
<li><img src="2.jpg" /></li>
<li><img src="3.jpg" /></li>
</ul>
CSS
ul {list-style:none;}
JavaScript
var options = {};
options.axis = "y";
options.containment = "parent";
options.cursor = "crosshair";
options.tolerance = "pointer";
options.revert = "true";
$('ul').sortable(options);