Freeze/Lock Web Page While Processing in ASP.Net

I would like to create a layer to cover a page while it is processing. First, downloading a loading icon from ajaxload. Then, you just need to paste following code in .aspx file.

UpdateProgress

UpdatePanel

Script Manager

CSS

.overlay  
{
    position: fixed;
    z-index: 98;
    top: 0px;
    left: 0px;
    right: 0px;
    bottom: 0px;
    background-color: #aaa; 
    filter: alpha(opacity=80); 
    opacity: 0.8; 
}
.overlayContent
{
    z-index: 99;
    margin: 250px auto;
    width: 80px;
    height: 80px;
}
.overlayContent h2
{
    font-size: 18px;
    font-weight: bold;
    color: #000;
}
.overlayContent img
{
    width: 60px;
    height: 60px;
}

Use UpdateProgress To Cover Screen

I have tried to browse it use chrome, firefox and ie and it works fine.