activeImage = new String(" ");   
function mouseOn(imgName){
	if ((document.images) && (imgName != activeImage)){
	     document[imgName].src = "../images/gifs/" + imgName + "_on.gif";
	}
}
function mouseOff(imgName){
	if ((document.images) && (imgName != activeImage)){
	   document[imgName].src = "../images/gifs/" + imgName + ".gif";
	}
}