function addLoadEvent(func) {
	var oldonload = window.onload;
	if (typeof window.onload != 'function')
	{
		window.onload = func;
	}
	else
	{
		window.onload = function()
		{
			oldonload();
			func();
		}
	}
}

function activateRollOvers()
{
	if(!document.getElementsByTagName)return false;
	var images = document.getElementsByTagName("img")

	for(i=0; i<images.length;i++)
	{	
		if (images[i].className.indexOf("rollover") == -1) continue;
			
		var urla = images[i].getAttribute("src").split(".");
		var ext = urla.pop();
		var filename = urla.join(".");
		images[i].img_over = filename + "_over.gif";
		if (filename.indexOf("_on") != -1) continue;
		images[i].img_out = filename + ".gif";
		
		var preloadImg = new Image();
		preloadImg.src = filename + "_over.gif";
		
		images[i].onmouseover = function()
		{
			this.setAttribute("src",this.img_over);
		}
		images[i].onmouseout = function()
		{
			this.setAttribute("src",this.img_out);
		}
		
	}
}

function addClass(element,value) 
{
	if (!element.className) 
	{
		element.className = value;
	}
	else 
	{
		newClassName = element.className;
		newClassName+= " ";
		newClassName+= value;
		element.className = newClassName;
	}
}

addLoadEvent(activateRollOvers);