JavaScript 读xml 运行报错,看了半天没错误啊,邦个忙啊!

readxml.html 页代码
<!DOCTYPE HTML PUBLIc "1//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtmll1-strict.dtd">
<html xmlns="http;//www.w3.org/1999/xhtml">
<head>
<title>xmlHttprequest</title>
<meta name="GENERATOR" content="Microsoft Visual Studio .NET 7.1">
<meta name="ProgId" content="VisualStudio.HTML">
<meta name="Originator" content="Microsoft Visual Studio .NET 7.1">
<script language="javascript">
    var xmlHttp;
    var requestType="";
   
    function createXMLHttpRequest()
    {   
         
       
        if(window.ActiveXObject)
        {
           
            xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
        }
        else(window.XMLHttpRequest)
        {
            xmlHttp=new XMLHttpRequest();
        }
    }
    
    function startRequest(requestedList)
    {   
       // alert("运行到这里!");
        requestType=requestedList;
        createXMLHttpRequest();
        alert("运行到这里!");
        xmlHttp.onreadystatechange=handleStateChange;
        xmlHttp.open("GET","city.xml",true);
        xmlHttp.send(null);
    
    }
    
    function handleStateChange()
    {   
        //alert("运行到这里!");
        if(xmlHttp.readyState==4)
        {
            if(xmlHttp.status==200)
            {
                if(requestType=="north")
                {
                    listNorthStates();
                }
                else if(requestType=="All")
                {
                
                    listAllStates();
                }
            }
    
        }         
     }
     
     function listNorthStates()
     {   
        //alert("运行到这里!");
         var xmlDoc=xmlHttp.responseXML;
         var northNode=xmlDoc.getElementsByTagName("north");
        // var out="Northen States";
         var northStates=norhtNode.getElementsByTagName("state");
         
         outputList("Northen States",northStates);
     }
     
     function listAllStates()
     {
         var xmlDoc=xmlHttp.responseXML;
         var allStates=xmlDoc.getElementsByTagName("state");
         
         outputList("All States",allStates);
     }
     
     function outputList(title,states)
     {
         var out=title;
         var currentStates=null;
         for(var i=0;i<states.length;i++)
         {
             currentStates=states[i];
             out=out + "\n-" +currentStates.childNodes[0].nodeValue;
         }
         alert(out);
     }
</script>
</head>
<body>
<FONT face="宋体"></FONT>

        <form>
            <input type=button value="All States here" onclick="startRequest('All');"/>
            <br>
            <br>
            <input type=button value="North States here" onclick="startRequest('states');">
        </form>
   </body>
</html>
city.xml 页代码<?xml version="1.0" encoding="utf-8" ?> 
<states>
    <north>
        <state>beijing</state>
        <state>shijiazhuang</state>
        <state>langfang</state>
    </north>
    <south>
        <state>guangzhou</state>
        <state>shenzhen</state>
        <state>xiamen</state>
    </south>
    <east>
        <state>shanghai</state>
        <state>wenzhou</state>
        <state>nanjing</state>
    </east>
    <west>
        <state>xizang</state>
        <state>guizhou</state>
        <state>yunnan</state>
    </west>
</states>