function menu_attach(parent, child, position)
{
  var p = document.getElementById(parent);
  var c = document.getElementById(child);

  p["menu_parent"]     = p.id;
  c["menu_parent"]     = p.id;
  p["menu_child"]      = c.id;
  c["menu_child"]      = c.id;
  p["menu_position"]   = position;
  c["menu_position"]   = position;

  c.style.position   = "absolute";
  c.style.left       = '0px';
  c.style.visibility = "hidden";
  c.style.width      = p.clientWidth;

  p.onmouseover = menu_show;
  p.onmouseout  = menu_hide;

}

function menu_show_aux(parent, child)
{
  var p = document.getElementById(parent);
  var c = document.getElementById(child);

  var top  = p.offsetHeight + 2;
  var left = 0;

  for (; p; p = p.offsetParent)
  {
    top  += p.offsetTop;
    left += p.offsetLeft;
  }

  c.style.position   = "absolute";
  c.style.top        = top +'px';
  c.style.left       = left+'px';
  c.style.visibility = "visible";
}


function menu_show()
{
  var p = document.getElementById(this["menu_parent"]);
  var c = document.getElementById(this["menu_child" ]);
  p.className = "main_menu_over";
  menu_show_aux(p.id, c.id);
  clearTimeout(c["menu_timeout"]);
}

function menu_hide()
{
  var c = document.getElementById(this["menu_child"]);
  var p = document.getElementById(this["menu_parent"]);
  c["menu_timeout"] = setTimeout("document.getElementById('"+c.id+"').style.visibility = 'hidden'; document.getElementById('"+p.id+"').className = 'main_menu';", 100);
}