function initPage()
{
	var main = document.getElementById("main");
	var boxHeight = main.offsetHeight;
	var mainHeight = document.documentElement.clientHeight;
	if (window.opera) mainHeight = document.body.clientHeight;
	if (navigator.appVersion.indexOf("Safari") != -1) mainHeight = self.innerHeight;
	marg = (mainHeight-boxHeight)/2;
	if (main)
		if (marg > 0) main.style.marginTop = marg + "px";
		else main.style.marginTop = "20px";
}

if (window.addEventListener){
	window.addEventListener("load", initPage, false);
	window.addEventListener("resize", initPage, false);
}
else if (window.attachEvent && !window.opera){
	window.attachEvent("onload", initPage);
	window.attachEvent("onresize", initPage);
}