var timer= new Array();
Number.prototype.NaN0=function(){return isNaN(this)?0:this;}

function getPosition(e){
	var left = 0;
	var top  = 0;
	while (e.offsetParent){
		left += e.offsetLeft + (e.currentStyle?(parseInt(e.currentStyle.borderLeftWidth)).NaN0():0);
		top  += e.offsetTop  + (e.currentStyle?(parseInt(e.currentStyle.borderTopWidth)).NaN0():0);
		e     = e.offsetParent;
	}
	left += e.offsetLeft + (e.currentStyle?(parseInt(e.currentStyle.borderLeftWidth)).NaN0():0);
	top  += e.offsetTop  + (e.currentStyle?(parseInt(e.currentStyle.borderTopWidth)).NaN0():0);
	return {x:left, y:top};
}

function swapImg(obj, img){
  obj.src = 'images/nav/'+img;
}

function showMenu(id){
  clearTimeout(timer[id]);
  var menu = document.getElementById(id);
  if(menu.getAttribute('parent')){
    var parent = document.getElementById(menu.getAttribute('parent'));
    var pos = getPosition(parent);
    if( parseInt(parent.getAttribute('menuLevel'))==1 ){
      menu.style.top = pos.y+20;
      menu.style.left = pos.x;
    }else{
      menu.style.top = pos.y;
      menu.style.left = pos.x+172;
    }
    menu.style.display = '';
  }
}
function keepMenu(){
  var count = keepMenu.arguments.length
  for (i = 0;i < count;i++){
    var id=keepMenu.arguments[i];
    clearTimeout(timer[id]);
  }
}
function hideMenu(id){
  document.getElementById(id).style.display = 'none';
}
function closeMenu(id){
  var count = closeMenu.arguments.length
  for (i = 0;i < count;i++){
    var id=closeMenu.arguments[i];
    timer[id] = setTimeout("hideMenu('"+id+"')", 100);
  }
}