function $(objId) {
    return document.getElementById(objId.toString());
}

function hideControl(id) {
    obj = $(id);
    obj.style.display = 'none';
    obj.style.visibility = 'hidden';
}

function showControl(id) {
    obj = $(id);
    obj.style.display = 'inline';
    obj.style.visibility = 'visible';
}