if (document.images) {
advancedon = new Image();
advancedon.src = "images/sm-star.gif";
advancedoff = new Image();
advancedoff.src = "images/spacer.gif";
}

function ShowHide(imgDocID,imgObjName) {
if (document.images) 
document.images[imgDocID].src = eval(imgObjName + ".src")
}