function centerbox() {
		document.getElementById("wrapper").style.position = "relative";
		document.getElementById("wrapper").style.height = "620px";
		document.getElementsByTagName("html")[0].style.marginBottom = "0";
		if(navigator.userAgent.indexOf("Mac")<0 || navigator.userAgent.indexOf("MSIE")<0) {
			var hangdown = parseInt((document.body.offsetHeight-620)/2)
			if (hangdown < 5) hangdown = 5;
			document.getElementById("wrapper").style.marginTop = "0";
			document.getElementById("wrapper").style.top = hangdown+"px";
		}
	}