function showHideLayer(sender) {
    var parentDiv = sender.parentNode;
    var img = sender.firstChild;
    var elems = parentDiv.getElementsByTagName("*");
    var fndContent = new RegExp('\\bListingContentOpen\\b');
    var fndImg = new RegExp('\\bExpandPanelImgOpen\\b');

    for (var k = 0, j = elems.length; k < j; k++)
        if (fndContent.test(elems[k].className) || fndImg.test(elems[k].className)) {
            if (elems[k].style.display == "none") {
                elems[k].style.display = "block";
                img.src = "/images/collapse.gif";
                img.alt = "Collapse";
            } else {
                elems[k].style.display = "none";
                img.src = "/images/expand.gif";
                img.alt = "Expand";
            }
        }
}