<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
<script src="Scripts/jquery.cookie.js" type="text/javascript"></script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList ID="TestDropDownList" runat="server">
<asp:ListItem Text="Please Select" Value="0"></asp:ListItem>
<asp:ListItem Text="FirstText" Value="1"></asp:ListItem>
<asp:ListItem Text="SecondText" Value="2"></asp:ListItem>
<asp:ListItem Text="ThirdText" Value="3"></asp:ListItem>
<asp:ListItem Text="FourthText" Value="4"></asp:ListItem>
</asp:DropDownList>
</div>
</form>
</body>
<script type="text/javascript">
$(function()
{
$('#<%= TestDropDownList.ClientID %>').change(function(e)
{
var selectedValue = this.value;
var date = new Date();
date.setTime(date.getTime() + (3 * 24 * 60 * 60 * 1000));
$.cookie('cookieName', 'theValue', { path: '/', expires: date });
});
});
</script>
</html>