var ImagesOver;
var ImagesOn;

function str_replace(search, replace, subject) {
    return subject.split(search).join(replace);
}

setRollovers=function()
{
	selects = document.getElementsByTagName("IMG");
	
	ImagesOver = new Array(selects.length);
	ImagesOn  = new Array(selects.length);
		
	for(I=0; I<selects.length; I++)
	{
		if((selects[I].className == "roll"))
		{
			ImagesOn[I] = new Image();
			ImagesOn[I].src = selects[I].src;
			ImagesOver[I] = new Image();
			ImagesOver[I].src = str_replace(".jpg","_over.jpg",selects[I].src);

			selects[I].onmouseover=function() 
			{
				this.src = str_replace(".jpg","_over.jpg",this.src);
			}
			selects[I].onmouseout=function() 
			{
				this.src = str_replace("_over.jpg",".jpg",this.src);
			}
		}
	}
}