function openWindow(thisUrl, w, h){
	screenwidth = screen.availWidth;
	screenheight = screen.availHeight;
	thisWidth = 640;
	thisHeight = 500;
	thisLeft = ((screenwidth - thisWidth)/2);
	thisTop = ((screenheight - thisHeight)/2);
	optionString = ('width=' + thisWidth + ',height=' + thisHeight + ',top=' + thisTop + ',left=' + thisLeft + ',status=no,menubar=no,resizable=yes,scrollbars=yes,toolbar=no');
	window.open(thisUrl,'',optionString);
}