function openWindow(URL, winName, width, height){

	if(height=='' || !height)
	height=screen.height/2
	height_factor = ((screen.height/100)*85)
	if(height>=height_factor)
		height=height_factor;


	if(width=='' || !width)
		width=screen.width/2
	width_factor = ((screen.width/100)*95)
	if(width>=width_factor)
		width=width_factor;

	var top=((screen.height-height)/2)-(screen.height/20)
	var left=(screen.width - width) / 2 ;

		win=window.open(URL, winName, 'toolbar=no,location=no,directories=no,status=0,menubar=no,scrollbars=yes,resizable=1,copyhistory=no,width='+width+',height='+height+',top='+top+',left='+left+'');
		win.focus();
}