This way
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script type = "text/javascript">
$("#lnk").live("click", function () {
window.location = 'MyPage.aspx?Id=' + $("#hid").val();
});
</script>
</head>
<body>
<form id="form1" runat="server">
<a id = "lnk" href = "javascript:;">Click</a>
<input type = "hidden" id = "hid" value = "101" />
</form>
</body>
</html>