var menuLayers = {
  timer: null,
  activeMenuID: null,
  offX: 4,   // horizontal offset 
  offY: 6,   // vertical offset 
  show: function(id, e) {
    var mnu = document.getElementById? document.getElementById(id): null;
    if (!mnu) return;
    this.activeMenuID = id;
    if ( mnu.onmouseout == null ) mnu.onmouseout = this.mouseoutCheck;
    if ( mnu.onmouseover == null ) mnu.onmouseover = this.clearTimer;
    viewport.getAll();
    this.position(mnu,e);
  },
  
  showAbs: function(id, e, obj, xOffset, yOffset) {
    var mnu = document.getElementById? document.getElementById(id): null;
    if (!mnu) return;
    this.activeMenuID = id;
    if ( mnu.onmouseout == null ) mnu.onmouseout = this.mouseoutCheck;
    if ( mnu.onmouseover == null ) mnu.onmouseover = this.clearTimer;
    viewport.getAll();
    this.positionAbs(mnu,e, obj, xOffset, yOffset);
  },
  
  hide: function() {
    this.clearTimer();
	var mnu_iframe = document.getElementById('mnu_iframe');
    mnu_iframe.style.visibility = 'hidden';
    if (this.activeMenuID && document.getElementById) 
      this.timer = setTimeout("document.getElementById('"+menuLayers.activeMenuID+"').style.visibility = 'hidden'", 0);
	 
  },
  
  positionAbs: function(mnu, e, obj, xOffset, yOffset) {
  
    var x = findPosX(obj) + xOffset;
    var y = findPosY(obj) + yOffset;
	var mnu_iframe = document.getElementById('mnu_iframe');
	
	mnu_iframe.style.top = y; //move iframe
	mnu_iframe.style.left = x; //move iframe
	mnu_iframe.style.width = mnu.offsetWidth;
	mnu_iframe.style.height = mnu.offsetHeight;
	
    mnu.style.left = x + "px"; mnu.style.top = y + "px";
	
	this.timer = setTimeout("document.getElementById('mnu_iframe').style.visibility = 'visible'", 0);
    this.timer = setTimeout("document.getElementById('" + menuLayers.activeMenuID + "').style.visibility = 'visible'", 0);
  },
  
  position: function(mnu, e) {
    var x = e.pageX? e.pageX: e.clientX + viewport.scrollX;
    var y = e.pageY? e.pageY: e.clientY + viewport.scrollY;
    
    if ( x + mnu.offsetWidth + this.offX > viewport.width + viewport.scrollX )
      x = x - mnu.offsetWidth - this.offX;
    else x = x + this.offX;
  
    if ( y + mnu.offsetHeight + this.offY > viewport.height + viewport.scrollY )
      y = ( y - mnu.offsetHeight - this.offY > viewport.scrollY )? y - mnu.offsetHeight - this.offY : viewport.height + viewport.scrollY - mnu.offsetHeight;
    else y = y + this.offY;
    
    mnu.style.left = x + "px"; mnu.style.top = y + "px";
    
	var mnu_iframe = document.getElementById('mnu_iframe');
	
	mnu_iframe.style.top = y; //move iframe
	mnu_iframe.style.left = x; //move iframe
	mnu_iframe.style.width = mnu.offsetWidth;
	mnu_iframe.style.height = mnu.offsetHeight;
	
	this.timer = setTimeout("document.getElementById('mnu_iframe').style.visibility = 'visible'", 0);
	this.timer = setTimeout("document.getElementById('" + menuLayers.activeMenuID + "').style.visibility = 'visible'", 200);
	
  },
  
  mouseoutCheck: function(e) {
    e = e? e: window.event;
    // is element moused into contained by menu? or is it menu (ul or li or a to menu div)?
    var mnu = document.getElementById(menuLayers.activeMenuID);
    var toEl = e.relatedTarget? e.relatedTarget: e.toElement;
    if ( mnu != toEl && !menuLayers.contained(toEl, mnu) ) menuLayers.hide();
  },
  
  // returns true of oNode is contained by oCont (container)
  contained: function(oNode, oCont) {
    if (!oNode) return; // in case alt-tab away while hovering (prevent error)
    while ( oNode = oNode.parentNode ) 
      if ( oNode == oCont ) return true;
    return false;
  },

  clearTimer: function() {
    if (menuLayers.timer) clearTimeout(menuLayers.timer);
  }
  
}
function findPosX(obj)
{
	var curleft = 0;
	if (obj.offsetParent)
	{
		while (obj.offsetParent)
		{
			curleft += obj.offsetLeft
			obj = obj.offsetParent;
		}
	}
	else if (obj.x)
		curleft += obj.x;
	return curleft;
}

function findPosY(obj)
{
	var curtop = 0;
	if (obj.offsetParent)
	{
		while (obj.offsetParent)
		{
			curtop += obj.offsetTop
			obj = obj.offsetParent;
		}
	}
	else if (obj.y)
		curtop += obj.y;
	return curtop;
}