//AJAX
Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginRequestHandler)
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequestHandler)

//var a = document.documentElement.clientHeight/2;
//var b = document.documentElement.clientWidth/2;

function beginRequestHandler() {
  var b = (screen.width / 2) + document.documentElement.scrollLeft;
  var a = (screen.height / 2) + document.documentElement.scrollTop;
  document.getElementById("progress").style.top = a - 10;
  document.getElementById("progress").style.left = b - 10;
  document.getElementById("progress").style.position = 'absolute'

  document.body.style.cursor = 'wait';
  document.getElementById("progress").style.display = '';
}
function endRequestHandler() {
  document.body.style.cursor = 'auto';
  document.getElementById("progress").style.display = 'none';
}
//AJAX