var tbody = document.getElementById("ctl00_allclass2_DataList_ParClass").childNodes[0];
var tr;
var ul;
var span;
var find = false;

for(var i=0;i<tbody.childNodes.length;i++)
{
 tr    = tbody.childNodes[i];
 ul    = tr.getElementsByTagName("ul")[0];
 span  = tr.getElementsByTagName("span")[0];

     if(ul.childNodes.length >0 )
     {
       span.innerHTML = '<img src="http://s.yizimg.com/Skins3/SB2703Skin/images/plus.gif" style="width: 9px; height: 9px;" alt="imgPlus"/>';
       span.mark = 'plus';
       
         
           if(location.href.toLowerCase().indexOf('category') > -1)
           {
              if(!find)
              {
                 if(span.nextSibling.href.toLowerCase() == location.href.toLowerCase() )
                 {
                   span.innerHTML = '<img src="http://s.yizimg.com/Skins3/SB2703Skin/images/minus.gif" style="width: 9px; height: 9px;" alt="minus"/>';
                   span.mark = 'minus'; 
                   span.parentNode.nextSibling.style.display = 'block';
                   find = true; 
                 }
               }
           }
           
          
           if(location.href.toLowerCase().indexOf('chiclass') > -1)
           {
              if(!find)
              {
                  var as = ul.getElementsByTagName('a');
                  
                  for(var j=0;j<as.length;j++)
                  {
                     if( as[j].href.toLowerCase() == location.href.toLowerCase() )
                     {
                        span.innerHTML = '<img src="http://s.yizimg.com/Skins3/SB2703Skin/images/minus.gif" style="width: 9px; height: 9px;" alt="minus"/>';
                        span.mark = 'minus'; 
                        span.parentNode.nextSibling.style.display = 'block';
                        find = true;
                     }
                  }
                
              }
           }
 
           span.onclick = function()
           {
               
               this.parentNode.nextSibling.style.display =  this.parentNode.nextSibling.style.display == "block" ?"none":"block";
               
               if(this.mark == 'plus')
               {
                   
                   this.innerHTML =  '<img src="http://s.yizimg.com/Skins3/SB2703Skin/images/minus.gif" style="width: 9px; height: 9px;" alt="minus"/>';
                   this.mark = 'minus';
               }
               else
               {   
                   this.innerHTML = '<img src="http://s.yizimg.com/Skins3/SB2703Skin/images/plus.gif" style="width: 9px; height: 9px;" alt="imgPlus"/>';
                   this.mark = 'plus';       
               }                    
           }
       
       
     }
 else
 {
    span.innerHTML = "&nbsp;&nbsp;"
    span.style.visibility="hidden";
 }
}