var  CustomDropDown = function(ddlid,t,current_value,buttonclass,animation){
	
	var tempset=false;
	var current=false;
	/*得到可用最大深度*/	
	var maxdepth=0;
	$("div").each(
		function(){
			maxdepth=Math.max(maxdepth,$(this).css("z-index")||0)   
		}
	)
	maxdepth+=10;
	
	/*初始化*/
	if(arguments.length==2){
		buttonclass="selectbox";
		tempset=true;
		animation=true;		
		current=true;
	}
	if(arguments.length==3){
		buttonclass="selectbox";		 
		animation=true;		
		current=true;
	}
	if(arguments.length==1){
		buttonclass="selectbox";
		animation=true;
	}
	
	$(ddlid).css({display:"none"})
	.wrap("<div class=\"DropDownListWrap\" style='z-index:1000;' ></div>")
	.after("<a href=\"javascript:;\" style=\"color:#DADBDC\" class=\""+buttonclass+"\" style=\"outline:none\">select category</a><div class=\"DropDownListMenu\"><ul></ul></div>")
	.focus(
		function(){
			$(this).blur();
		}
	).next().next().css({
		width:$(ddlid).next().width()-2	
	})
				
	//$("DropDownListMenu").fadeTo(0,0.5)			
	/*获得下拉表的数据*/	
	$(ddlid).children().each(
		function(){	
			var _content=$(this).html()
			_content=_content.length<=29?_content:_content.substring(0,32)+"...";
			$(ddlid).parent().find(".DropDownListMenu ul").append("<li title=\""+$(this).attr("value")+"\">"+_content+"</li>");
			if($(this).attr("value")==$(ddlid).val()){
				$(ddlid).next().html($(this).html());
			}	
			if(current){
				$(ddlid).next().html(current_value);
			}
		}
	);
	
	
	/*根据下拉表内容确定是否显示下拉条*/
	 $(ddlid).next().next().css({
			overflow:$(ddlid).children("option").length<10?"hidden":"auto",
			height:$(ddlid).children("option").length<10?($(ddlid).children("option").length*18+8)+"px":"200px"		
	}); 
	 
	  
	/*按钮事件*/
	var clicked=false;
	$(ddlid).next().click(
		function(e){	
			if(!clicked){
				if(!tempset){
					e.preventDefault() ;	
					if(animation){
						$(".DropDownListMenu").slideUp(400);	
						$(ddlid).next().next().slideDown(400);					
					}else{
						$(ddlid).next().next().show();
					}
				}
				clicked=true;
			}else{				 
				$(ddlid).next().next().slideUp(400);
				clicked=false;
			}		 
		}
	)
	.focus(
		function(e){
			$(this).blur();
			e.stopPropagation();	
		}
	)
	
	/*模拟下拉表点击事件*/
	$(ddlid).parent().find(".DropDownListMenu ul li").click(
		function(){
			clicked=false;
			var _content=$(this).html();
			_content=_content.length<=23?_content:_content.substring(0,26)+"...";
			$(ddlid).next().html(_content)
			.attr("title",$(this).attr("value"));			
			$(this).parent().parent().hide();	
			$(ddlid).children("option").each(								
				function(){	
					if($(this).html()==$(ddlid).next().text()){
						$(this)[0].selected=true;
					}
				}
			)
		}
	).hover(
		function(){
			$(this).addClass("DropDownListRollOver");			
		},
		function(){
			$(this).removeClass("DropDownListRollOver");			
		}
	)
	
	/*点击空白处消失*/
	$(document).click(
		function(e){
			if(e.target.className!=buttonclass){			
					if(animation){					
						$(ddlid).next().next().slideUp(400);	
					}else{
						$(ddlid).next().next().hide();
					}
			}
		}
	)
	
}