function ro_imgNormal(imgName) {
    if (document.images) {
        document[imgName].src = eval(imgName + "_n.src");
        self.status = '';
    }
}
function ro_imgOver(imgName, descript) {
    if (document.images) {
        document[imgName].src = eval(imgName + "_o.src");
        self.status = descript;
    }
}