It is jQuery UI SelectMenu Plugin
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Untitled Page</title>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script src="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.9/jquery-ui.js" type="text/javascript"></script>
<link href="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.9/themes/blitzer/jquery-ui.css"
rel="stylesheet" type="text/css" />
<script type="text/javascript" src="http://jquery-ui.googlecode.com/svn/branches/labs/selectmenu/ui.selectmenu.js"></script>
<link rel="Stylesheet" href="http://jquery-ui.googlecode.com/svn/branches/labs/selectmenu/ui.selectmenu.css"
type="text/css" />
<script type="text/javascript">
$(function () {
$("[id*=DropDownList1]").selectmenu({
style: 'dropdown',
menuWidth: 400,
format: addressFormatting
});
var addressFormatting = function (text) {
var newText = text;
//array of find replaces
var findreps = [
{ find: /^([^\-]+) \- /g, rep: '<span class="ui-selectmenu-item-header">$1</span>' },
{ find: /([^\|><]+) \| /g, rep: '<span class="ui-selectmenu-item-content">$1</span>' },
{ find: /([^\|><\(\)]+) (\()/g, rep: '<span class="ui-selectmenu-item-content">$1</span>$2' },
{ find: /([^\|><\(\)]+)$/g, rep: '<span class="ui-selectmenu-item-content">$1</span>' },
{ find: /(\([^\|><]+\))$/g, rep: '<span class="ui-selectmenu-item-footer">$1</span>' }
];
for (var i in findreps) {
newText = newText.replace(findreps[i].find, findreps[i].rep);
}
return newText;
}
});
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:DropDownList ID="DropDownList1" runat="server" Width="200">
<asp:ListItem>John Doe - 78 West Main St Apt 3A | Bloomsburg, PA 12345 (footer text)</asp:ListItem>
<asp:ListItem>Joseph Doe - 78 West Main St Apt 3A | Bloomsburg, PA 12345 (footer text</asp:ListItem>
<asp:ListItem>Mad Doe Kiiid - 78 West Main St Apt 3A | Bloomsburg, PA 12345 (footer text)</asp:ListItem>
</asp:DropDownList>
</form>
</body>
</html>
Ref: http://jquery-ui.googlecode.com/svn/branches/labs/selectmenu/index.html
Blog: http://filamentgroup.com/lab/jquery_ui_selectmenu_an_aria_accessible_plugin_for_styling_a_html_select/
