function scrollDoor(){
		}
		scrollDoor.prototype = {
		 sd : function(menus,divs,openClass,closeClass){
		  var _this = this;
		  if(menus.length != divs.length)
		  {
		   alert("菜单层数量和内容层数量不一样!");
		   return false;
		  }    
		  for(var i = 0 ; i < menus.length ; i++)
		  { 
		   _this.$(menus[i]).value = i;    
		   _this.$(menus[i]).onmouseover = function(){
		     
		    for(var j = 0 ; j < menus.length ; j++)
		    {      
		     _this.$(menus[j]).className = closeClass;
		     _this.$(divs[j]).style.display = "none";
		    }
		    _this.$(menus[this.value]).className = openClass; 
		    _this.$(divs[this.value]).style.display = "block";    
		   }
		  }
		  },
		 $ : function(oid){
		  if(typeof(oid) == "string")
		  return document.getElementById(oid);
		  return oid;
		 }
		}