function enableElement(whichElement, bEnable) 
{
    if (document.getElementById) // standard
        document.getElementById(whichElement).disabled = !bEnable; 
    else if (document.all) // old MSIE
        document.all[whichElement].disabled = !bEnable;
    else if (document.layers) // nn4
        document.layers[whichElement].disabled = !bEnable;
}