//JavaScript code included at jsUpdateProgress.js file
Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginReq); 
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endReq);    

function beginReq(sender, args){     
    // shows the Popup     
    $find(ModalProgress).show();        
}  

function endReq(sender, args) {     
    //  shows the Popup     
    $find(ModalProgress).hide(); 
}