function openWindow(url,w,h){
			
			var winl = (screen.width-w)/2;
			var wint = (screen.height-h)/2;
			if (winl < 0) winl = 0;
			if (wint < 0) wint = 0;
		
			var windowProps = "toolbar=0,scrollbars=1,resizable=1,height=" + h + ", width = " + w + ", left = " + winl + ", top = " + wint;
		
			window.open(url, "popup", windowProps)
}