This the code. I invoke this on the webform when button is clicked.
<style type="text/css">
.auto-style1 {
width: 100%;
}
.modal {
position: fixed;
top: 0;
left: 0;
background-color: black;
z-index: 99;
opacity: 0.8;
filter: alpha(opacity=80);
-moz-opacity: 0.8;
min-height: 100%;
width: 100%;
}
.loading {
font-family: Arial;
font-size: 10pt;
border: 5px solid #67CFF5;
width: 200px;
height: 100px;
display: none;
position: fixed;
background-color: White;
z-index: 999;
}
.auto-style2 {
color: #CC3300;
}
.auto-style3 {
color: #FF9900;
}
.auto-style4 {
color: #006600;
}
</style>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
function ShowProgress() {
setTimeout(function () {
var modal = $('<div />');
modal.addClass("modal");
$('body').append(modal);
var loading = $(".loading");
loading.show();
var top = Math.max($(window).height() / 2 - loading[0].offsetHeight / 2, 0);
var left = Math.max($(window).width() / 2 - loading[0].offsetWidth / 2, 0);
loading.css({ top: top, left: left });
}, 200);
}
$('form').live("submit", function () {
ShowProgress();
});
</script>