function setCurrentNav() {
	var els = $("main_nav").getElementsByTagName("a");
	var href = window.location.href.replace(/^.*\//, "");	
	$A(els).each(function(el) {
		var elHref = el.href.replace(/^.*\//, "");
		if(elHref == href || (elHref == "index.html" && href == "")) {
			var s = document.createElement("span");
			s.innerHTML = el.innerHTML;
			el.parentNode.replaceChild(s, el);
		}
	});
}
//Event.observe(window, "load", setCurrentNav);

function back2top() {
	window.scrollTo(0,0);
}