Trouble Reading this XML file from javascript

I have the following XML file...
<?xml version="1.0" encoding="UTF-8" ?>
<company>
  <employee id="001" sex="M" age="19" name="A"></employee>
  <employee id="002" sex="M" age="24" name="B"></employee>
  <employee id="003" sex="M" age="21" name="C"></employee>
</company>

Above file name is "employee.xml" on the server.
All I want is
1. To find how many employee elements we have
2. To number of employee elements, loop it and pick up each ones id', sex, age, name and display (for now an alert message is fine)

I want to write a piece of AJAX to do this.
So I wrote.,...

<script type="text/javascript">
        var xmlDoc;
        function loadXML() {
            xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
            xmlDoc.async = false;
            xmlDoc.onreadystatechange = readXML;
            xmlDoc.load("employees.xml");
        }

        function readXML() {
            if (xmlDoc.readyState == 4) {
                //Using documentElement Properties
                //Output company
                alert("XML Root Tag Name: " + xmlDoc.documentElement.tagName);
                alert("Num Nodes: " + xmlDoc.childNodes(0).valuOf);
                alert("Num Nodes: " + xmlDoc.childNodes(1).hasChildNodes());
                alert("Num Nodes: " + xmlDoc.childNodes(2).hasChildNodes());
               
            }
        }
</script>

I do not get the answers I expect. Can some one help?