function openWindow(url, name, width, height) {
  var x = parseInt(screen.width / 2.0) - (width / 2.0);
  var y = parseInt(screen.height / 2.0) - (height / 2.0);
	  
  var win = window.open(url, name, 'left=' + x + ',top=' + y + ',width=' + width + ',height=' + height + ', scrollbars=no, dialog=yes');
  return win;
}