function navigationMouseOver(img){
	if(!img)
		return;
	var src = img.src;
	var ext = ".gif";
	var highlight = "-a";
	var split = src.split(ext);
	src = split[0]+highlight+ext;
	img.src = src;
}

function navigationMouseOut(img){
	if(!img)
		return;
	var src = img.src;
	var ext = ".gif";
	var highlight = "-a";
	var split = src.split(highlight+ext);
	src = split[0]+ext;
	img.src = src;
}