function get_element(id) {
    if (document.layers) {return document.layers[id];}
    else if (document.all) {return document.all[id];}
    else if (document.getElementById) {return document.getElementById(id);}
    else {return null;}
}
function show(s_id) {
    var x = get_element(s_id);
    x.style.display = 'block';
    x.style.visibility = 'visible';
}
function hide(h_id) {
    var x = get_element(h_id);
    x.style.display = 'none';
    x.style.visibility = 'hidden';
}