/* **********
 * h2 をメニューにして h1 の次に加える
 * withback();
 * onloadの書き方は拡張性のため
                 2009-2010 adachi
                     ************ */
window.onload = function(){
  withback();
}
function withback() {
   var topstr = "topelementdefbyjavascript";
   var targetp = document.getElementsByTagName("h1");
   targetp[0].setAttribute("id",topstr);
   var items = document.getElementsByTagName("h2");
   var olist = document.createElement("ol");

   for(var i=0;items.length>i;i++){
   　if(items[i].firstChild == null)continue;
      var toptext = document.createTextNode("▲");
      var toplink = document.createElement("a");
      toplink.appendChild(toptext);
      toplink.href = "#" + topstr;

      var fragm = items[i].getAttribute("id");
      var titlestring = items[i].firstChild.nodeValue;
      var text = document.createTextNode(titlestring);
      var listitem = document.createElement("li");
      var link = document.createElement("a");
      link.appendChild(text);
      listitem.appendChild(link);
      olist.appendChild(listitem);
      link.href = "#"+fragm;
      items[i].appendChild(toplink);
   }
   var nextp = targetp[0].nextSibling;
   targetp[0].parentNode.insertBefore(olist,nextp);
   olist.style.borderTop = "solid 2px #ccffcc";
   olist.style.borderBottom = "solid 2px #ccffcc";
}