function showSubMenu(aId, aIconId)
{
    var theElement = document.getElementById(aId);
    var theIcon = document.getElementById(aIconId);
    
    if (theElement.style.display == 'none')
    {
//        alert(""+aId+", "+aIconId);
        theElement.style.display = 'block';
        theIcon.src = 'images/minus.gif';
    } else
    {
//        alert(""+aId+", "+aIconId);
        theElement.style.display = 'none';
        theIcon.src = 'images/plus.gif';
    }
}