document.joe = new Object();

document.joe.iOut = new Image();
document.joe.iOut.src = "images/navout.gif";

document.joe.iOver = new Image();
document.joe.iOver.src = "images/navover.gif";

function joeMouseOver( s )
{
	document.images[s].src= document.joe.iOver.src;
}

function joeMouseOut( s )
{
	document.images[s].src= document.joe.iOut.src;
}