Add follwoing script to your head tag
<script type="text/javascript">
$(document).ready(function () {
$("#Button2").click(function () {
var eID = document.getElementById("MyDiv");
callit(eID);
});
});
function callit(cid) {
$(cid).hide();
}
</script>
Put Following markup in head tag
<div id="MyDiv">This is my div</div>
<input id="Button2" type="button" value="button" />
</div>
Note: Do not forget to add jquery link in your page
Hope This Helps!!!