遍歷form中所有的控件

<script language="javascript" type="text/javascript">
 function walktree(level,tree)
 {
  var textArea = document.getElementById("TextArea1");
  var numItems = tree.length;
  for(var i = 0; i < numItems; i++)
  {
   var item = tree.item(i);
   textArea.value += level + " " + item.tagName + "/n";
   if(item.hasChildNodes)
   {
    walktree.(level+1,item.childNodes);
   }
  }
 }
</script>

<input id="b1" type="button" value="Click" onClick="walktree(0,form.childNodes);"/>