var prevId;
function show_hide_menu(Id)
{

if(prevId > 0 && prevId != Id)
    {
    document.getElementById("menu_"+prevId).style.display = "none";
    document.getElementById("image_"+prevId).className = "katBull";
    }
  
    if(document.getElementById("menu_"+Id).style.display == "none")
        {
        document.getElementById("menu_"+Id).style.display = "block";
        document.getElementById("image_"+Id).className = "katBullOn";
        }
    else
        {
        document.getElementById("menu_"+Id).style.display = "none";
        document.getElementById("image_"+Id).className = "katBull";
        }
    prevId = Id;
}