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=0,copyhistory=no,width='+width+',height='+height+',top='+top+',left='+left+'');
			win.focus();
	}