function changeOver(){
    var e = window.event.srcElement;

    if (e.oversrc == null)
        return;

    if (e.cur == "false")
        e.src = e.oversrc;
}

document.onmouseover = changeOver;

function changeOut(){
    var e = window.event.srcElement;

    if (e.orgsrc == null)
        return;

    if (e.cur == "false")
        e.src = e.orgsrc;
}

document.onmouseout = changeOut;