function openPopup() {
	var offset = 0;

	var width = 1000;
	var height = 700;
	 
	var left = (screen.width-width)/2;
	var top = (screen.height-(height+110))/2;
	
	if ( navigator.appName.indexOf("Firefox") != -1 && navigator.appName.indexOf("Mac") != -1) offset = 16;

	open("philippundkeuntje.php", "pundk", "width=1000,height="+(700+offset)+",left="+left+",top="+top);
	
	return false;
}