function show_submenu(Id) 
{
    try 
    {
        
        loadMenue(Id);
        element = document.getElementById(Id);

        if (element != null) element.style.display = element.style.display == 'block' ? 'none' : 'block';
    } 
    catch (e) 
    {
        alert("Error: " + e);
    }
}

function loadMenue(Id) 
{
    if (Id != 'register') document.getElementById('register').style.display = 'none';
    if (Id != 'nosubmenue') document.getElementById('nosubmenue').style.display = 'none';
}