isNS4 = (document.layers) ? true : false;
isIE4 = (document.all && !document.getElementById) ? true : false;
isIE5 = (document.all && document.getElementById) ? true : false;
isNS6 = (!document.all && document.getElementById) ? true : false;

var visibleLayer = new Array();
var timer;

function showMenu (layerName, imgRef, parentLayer) {
  if (isIE5 || isNS6) {
   alert("1");
   while (visibleLayer.length > 0) {
  alert("2");
      lastLayer = visibleLayer[visibleLayer.length - 1];
      if (lastLayer != parentLayer && lastLayer != layerName)
      {
  alert("3");
        elm = document.getElementById(lastLayer);
        elm.style.visibility = "hidden";
        visibleLayer.pop();
      } else {
			break;
      }
    }

    if (layerName != null) {
  alert("4");
      elm = document.getElementById(layerName);
      elm.style.top = getY(imgRef, parentLayer);
      elm.style.visibility = "visible";
      visibleLayer.push(layerName);
    }

	return;
  }

  if (isNS4) {
   alert("5");
   if (visibleLayer != null) {
  alert("6");
      document.layers[visibleLayer].visibility = "hide";
      visibleLayer = null;
    }

    if (layerName != null) {
  alert("7");
      document.layers[layerName].visibility = "show";
    }
  }
}

function getY(imgID, parentLayer) {
/*    if (isNS4 || isNS6) {

    	yPos

    	return eval(imgID).y

    else {*/
        yPos = eval(imgID).offsetTop;
		tempEl = eval(imgID).offsetParent;

		while (tempEl != null) {
		    yPos += tempEl.offsetTop;
		    tempEl = tempEl.offsetParent;
		}

		return yPos;
//    }
}

function hideMenu () {
  window.status="Out";
  timer = setTimeout("clearAllMenus()", 500);
}

function clearAllMenus() {
	while (visibleLayer.length > 0) {
		thisLayer = visibleLayer.pop();
		elm = document.getElementById(thisLayer);
		elm.style.visibility = "hidden";
	}
}

function clearSubMenus(layerName) {
  while (visibleLayer.length > 0) {
    if (layerName != visibleLayer[visibleLayer.length - 1]) {
        subMenu = visibleLayer.pop();
		elm = document.getElementById(subMenu);
		elm.style.visibility = "hidden";
    } else {
      break;
    }
  }
}