if (document.images) {
 img_on =new Image();  img_on.src ="/images/home_banner_on.jpg"; 
 img_off=new Image();  img_off.src="/images/home_banner_off.jpg"; 
}

function handleOver() { 
 if (document.images) document.imgName.src=img_on.src;
}

function handleOut() {
 if (document.images) document.imgName.src=img_off.src;
}