日期:2014-05-18  浏览次数:20553 次

急!刚学习ajax,在访问xml文档时出现xmlHttp.readystate为空或不是对象错误。
问题:想使用ajax功能实现访问XML文档,取出文档中的部分数据
错误信息:xmlHttp.readystate为空或不是对象
补充:在访问文本文件时没有出现错误。

请大家帮忙!谢谢

USstates.xml文档,表示美国州的名字并按方位分类了,内容如下:
<?xml version="1.0" encoding="utf-8" ?>
<states>
  <north>
  <state>Minnesota</state>
  <state>Iowa</state>
  <state>North</state>
  </north>
  <east>
  <state>New York</state>
  <state>North Carolina</state>
  <state>Massachusetts</state>
  </east>
  <south>
  <state>Texas</state>
  <state>OKlahoma</state>
  <state>Louisiana</state>
  </south>
  <west>
  <state>Calinfornia</state>
  <state>Oregon</state>
  <state>Nevada</state>
  </west>
</states>
想通过点击htm页中的按钮显示north方向国家的名称:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
  <title>练习</title>
  <script type ="text/javascript" >
  var xmlHttp;
  var requestType;
   
  function createXmlHttpRequest()
  {
  if(window.ActiveXObject)
  {
  xmlHttp = new ActiveXObject("Microsoft.XMLHttp");
  }
  else if(window.XMLHttpRequest)
  {
  xmlHttp = new XMLHttpRequest();
  }
  }
  function startRequest(requestList)
  {
  requestType = requestList;
  createXmlHttpRequest();
  xmlHttp.onreadystatechange=handleStateChange;
  xmlHttp.open("Get","USstates.xml",true);
  xmlHttp.send(null);
  }
  function handleStateChange()
  {
  if(xmlHttp.readystate == 4)
  {
  if(xmlHttp.status == 200)
  {
  if(requestType=="north")
  {
  listNorthStates();
  }
  else if(requestType=="all")
  {
  listAllStates();
  }
  }
  }
  }
  function listNorthStates()//显示north部分的国家
  {
  var xmlDoc = xmlHttp.responseXML;
  var northNode = xmlDoc.getElementByTagName("north")[0];
  var out = "Northern States";
  var northStates = northNode.getElementByTagName("state")[0];
  outputList(out,northStates);
  }
  function outputList(title,states)
  {
  var out = title;
  var currentState = null;
  for(var i = 0;i < states.Length;i++)
  {
  currentState = states[i];
  out = out + "/n- " + currentState.childNodes[0].nodeValue;
  }
  window.alert(out);
  }
  </script>
</head>
<body style="text-align: center">
  <h2>Process XML Document Of