if (document.images) {
nav = new Image(); nav.src = "/images/navEck.gif";
nava = new Image(); nava.src = "/images/navEck_a.gif";

}
function chgImg(imgName, newSrc) {
    var objImg = getImg(document, imgName);
    if (objImg) {
         eval('objImg.src = ' + newSrc + '.src');
    }
}
function getImg(doc, name) {
    var tmpImg = false;
    if (doc.images) tmpImg = doc.images[name];
    if (tmpImg) return tmpImg;
    if (doc.layers) {
	var x = doc.layers.length;
        for (var i = 0; i < x; i++) {
            tmpImg = getImg(doc.layers[i].document, name);
            if (tmpImg) return (tmpImg);
        }
    }
    return (false);
}