<script src="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.14/jquery-ui.min.js"></script>
<link rel="stylesheet" href="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.14/themes/black-tie/jquery-ui.css">
<ol>
<li>Type "ac" to get "ActionScript" in the suggestion list.</li>
<li>Press the "DOWN" arrow to focus on the item and populate the input</li>
<li>Move your mouse over the "ActionScript" suggestion</li>
<li>The input's value will be reset to "ac"</li>
</ol>
<input type="text" id="auto" />
CSS
ol { margin-left: 30px; list-style-type: decimal; }