title: javascript problems for IE and FF
body: <p>Could anyone please help me on this problem. The error message saying “object doesn't support this property of method, line 113, characters 5, url: <a href="http://xxxx.com/js/category.js" rel="nofollow">http://xxxx.com/js/category.js</a>”  appears when I try to open some site by several IE browsers. I assume that the script called category.js has some problems, or is not just suited for IE browsers. The category.js is used to open and close several levels of category, and the line 113 of category.js is listed below. (No problem for chrome and safari, and some css problem for Opera. IE and FF has never been worked.)</p>
  
  <pre><code>function initCategoryList(){
      var lv = 0;
  
      while(document.getElementsByClassName("level" + (++lv)).length){ // line 113
  
          for (var i = 0; i &lt; document.getElementsByClassName("level" + lv).length; i++) {
              setclickevent(document.getElementsByClassName("level" + lv)[i], lv, i);
          }
      }
  }
  </code></pre>