求高手帮忙看下这段jsp代码写的页面树有什么问题

在点击第六个二级分类时总是点不开，求帮忙，很急
function Show(id,i_id){
	        var on_img="images/open.png";
	        var off_img="images/close.png";
	        var obj=document.getElementById('c_'+id);
	        if(obj.style.display=="none"){
	                obj.style.display="";
	        i_id.src=on_img;
	        var curShow = readCookie('curShow');
	        if(curShow!='')
	        {
	          var arr_curShow = curShow.split(',');
	          var found = false;
	          for(i=0;i<arr_curShow.length-1;i++)
	          {
	            if(arr_curShow[i].toString()==id) {found=true;}
	          }
	          if(!found){writeCookie('curShow',curShow+','+id,12)}
	        }
	        else {
	          writeCookie('curShow',id,12)
	        }
	        }else{
	                obj.style.display="none";
	        i_id.src=off_img;
	        var curShow = readCookie('curShow');
	        if(curShow!='')
	        {
	          var arr_curShow = curShow.split(',');
	          for(i=0;i<arr_curShow.length;i++)
	          {
	            if(arr_curShow[i].toString()==id) {arr_curShow=arr_curShow.del(i--);}
	          }
	          curShow = arr_curShow.join(',');
	          //alert(curShow);
	          writeCookie('curShow',curShow,12)
	        }
	        }
		}

function readCookie(name)
		{
			var cookieValue = "";			
			var search = name + "=";			
			if(document.cookie.length > 0)			
			{ 			
			    offset = document.cookie.indexOf(search);			
			    if (offset != -1)			
			    { 			
			      offset += search.length;			
			      end = document.cookie.indexOf(";", offset);			
			      if (end == -1) end = document.cookie.length;			
			      cookieValue = unescape(document.cookie.substring(offset, end))			
			    }			
			}			
			return cookieValue;			
		}

		function writeCookie(name, value, hours)
		{		
			var expire = "";			
			if(hours != null)			
			{			
			    expire = new Date((new Date()).getTime() + hours * 3600000);			
			    expire = "; expires=" + expire.toGMTString();			
			}			
			document.cookie = name + "=" + escape(value) + expire;
			
		}
Array.prototype.del=function(n) {
			if(n<0) 
			    return this;
			else
			    return this.slice(0,n).concat(this.slice(n+1,this.length));
		}
window.onload = function a()
		{
			var curShow = readCookie('curShow');
			var totalShow = 7; //自己修改一共有多少个二级分类
			if(curShow!=''&&curShow!=null)
			{
			    for(i=1;i<=totalShow;i++)
			    {
			      document.getElementById('c_'+i).display="none";
			    }
			    var arr_curShow;
			    arr_curShow = curShow.split(',');
			    for(i=0;i<=arr_curShow.length-1;i++)
			    {
			      if(arr_curShow[i]!=''){document.getElementById('c_'+arr_curShow[i]).style.display="";}
			    }			
			}
		}

追问：我改了，但好像还是没用啊