<html>
<body>
<div id="div1">
<div id="div3">
</div>
</div>
<div id="div2">
</div>
<script>
function $id(id){
return document.getElementById(id);
}
function CountNodes(arr){
var len = arr.length;
var i = 0;
while(len--){
(arr[len].nodeType==1) && i++;
}
return i;
}
window.onload = function(){
alert(CountNodes($id("div2").childNodes));
$id("div2").appendChild($id("div3"));
alert(CountNodes($id("div1").childNodes));
alert(CountNodes($id("div2").childNodes));
}
</script>
</body>
</html>
