//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(); 
}