text: var tencentnav={
  	buildnav:function($, setting){		 
  		var $navobj=$("#"+setting.navid+">ul")
  		$navobj.parent().get(0).className=setting.classname || "nav"
  		var $parentobj=$navobj.find("ul").parent()
  		$parentobj.hover(
  			function(e){ $(this).children('a:eq(0)').addClass('on') },
  			function(e){ $(this).children('a:eq(0)').removeClass('on') }
  		)
  		$parentobj.each(function(i){
  			var $obj=$(this).css({zIndex: 999-i})
  			var $subul=$(this).children('ul:eq(0)')
  			this.datas={w:this.offsetWidth, h:this.offsetHeight,ulw:$subul.width(), ulh:$subul.height()}
  			this.istop =$obj.parents("ul").length==1? true : false
  			$subul.css({top:this.istop && setting.orientation!='v'? this.datas.h+"px" : 0})
  			$obj.hover(function(e){
  				var $playobj=$(this).children("ul:eq(0)")
  				this._offsets={left:$(this).offset().left, top:$(this).offset().top}
  				var mleft=this.istop && setting.orientation!='v'? 0 : this.datas.ulw
  				mleft=(this._offsets.left+mleft+this.datas.ulw>$(window).width())? (this.istop && setting.orientation!='v'? -this.datas.ulw+this.datas.w : -this.datas.w) : mleft 
  				$playobj.css({left:mleft+"px", width:this.datas.ulw+'px',display:'block'})
  
  			},function(e){
  				$(this).children("ul:eq(0)").css({display:'none'})			 
  			})
  		});
  		$navobj.find("ul").css({display:'none', visibility:'visible'})
  	},
  
  	init:function(setting){	
  		jQuery(document).ready(function($){
  			tencentnav.buildnav($, setting)
  		})
  	}
  }