Something

function fade(target) {
	if (target) fadeIn(target);
}

function fadeIn(target, opacity) {
	if (!opacity) opacity = 0;
	target.style.visibility = "visible";
	if (opacity <= 100) {
		if (typeof target.style.MozOpacity !== 'undefined')
			target.style.MozOpacity = (opacity/100)-.001;
		else if (typeof target.style.opacity !== 'undefined')
			target.style.opacity = (opacity/100)-.001;
		else if (typeof target.style.filter !== 'undefined')
			target.style.filter = "alpha(opacity="+opacity+")";
		opacity += 10;
		window.setTimeout(function(){fadeIn(target, opacity);}, 50);
	}
}