function hideDiv(whichLayer) {
    var elem, vis;
    elem = getElem(whichLayer);
    vis = elem.style;
    vis.display = 'none';
}

function showDiv(whichLayer) {
    var elem, vis;
    elem = getElem(whichLayer);
    vis = elem.style;
    vis.display = 'block';
}

function getElem(whichLayer) {
    if (document.getElementById)
        elem = document.getElementById(whichLayer);
    else if (document.all)
        elem = document.all[whichLayer];
    else if (document.layers)
        elem = document.layers[whichLayer];
    return elem;
}

function toggleDiv(whichLayer) {
    var elem, vis;
    elem = getElem(whichLayer);
    vis = elem.style;
    if (vis.display == '' && elem.offsetWidth != undefined && elem.offsetHeight != undefined)
        vis.display = (elem.offsetWidth != 0 && elem.offsetHeight != 0) ? 'block' : 'none';
    vis.display = (vis.display == '' || vis.display == 'block') ? 'none' : 'block';

    return elem;
}