jQueryUI 1.8.14 Autocomplete

HTML

<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">
<input type="text" id="auto" />

JavaScript

$("#auto").autocomplete({ 
    source: ['hi', 'bye', 'foo', 'bar'],
    minLength: 0
});

$("#auto").bind("focus", function () {
    this.value = '';
    $(this).autocomplete("search", '');
});