为什么我的PHP ajax调用失败了?

我对Ajax很陌生,但我正在尝试创建Ajax&>PHP连接,代码如下。

file1.php

<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>   
</head>
<input type="text" id='demo'>
<input type="button" onclick='ajaxCall()' value='23' >
<script>
function ajaxCall()
{
document.getElementById('demo').value="343434";   
xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange=function(){
  if(xmlhttp.requeststate==4 && xmlhttp.status==200){
    document.getElementById('demo').value="4444343434";   
    document.getElementById('demo').value=xmlhttp.responseText;
  }
 }
xmlhttp.open("GET","test.php",true);
xmlhttp.send();
}
</script>
</body>
</html>

和相应的test.php:

<?php
echo "me";
?>

现在,当我单击该按钮时,TextBox的值将更改为343434,但在ajax调用中不会更改,即使它不会更改为4444343434。我目前正在ubuntu14.04LTS上运行php5.5.6。

Change xmlhttp.requeststate to xmlhttp.readyState

Try use the following crossbrowsing function

function getXmlHttp(){
  var xmlhttp;
  try {
    xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
  } catch (e) {
    try {
      xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
    } catch (E) {
      xmlhttp = false;
    }
  }
  if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
    xmlhttp = new XMLHttpRequest();
  }
  return xmlhttp;
}

And change xmlhttp = new XMLHttpRequest(); to xmlhttp = new getXmlHttp();

And this work without jQuery.