function popUp (URLStr, left, top, width, height)
			{ 
			left = (screen.width - width)/2;
			top = (screen.height - height)/2;
			
			popUpWin = open(URLStr,'_blank','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbar=no,resizable=no,copyhistory=yes,width='+width+',height='+height+',left='+left+', top='+top+',screenX='+left+',screenY='+top+'');
	  		}