PHP编程实战15-4

<!--PHP编程实战-->
<!--JSON & Ajax -->
<!--15-4-->
<!--基本的XMLHttpRequest(异步)-->
<script type="text/javascript">
    var xhr = new XMLHttpRequest();
    xhr.open("GET", "animal.xml");
    xhr.onreadystatechange = function () {
        if (xhr.readyState == 4) {
            if (xhr.status == 2000) {
                alert('success');
            }
            else {
                alert("error");
            }
        }
    }
    xhr.send("our content");
</script>