<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>一个简单的不涉及服务器的Ajax实例</title>
<script type="text/javascript">
// 声明一个引用 XMLHttpRequest 的变量
var xhr = null;
// 选择一个著作时调用的函数
function updateCharacters() {
var selectShow = document.getElementById("selShow").value;
if (selectShow == "") {
document.getElementById("divCharacters").innerHTML = "";
return ;
}
// 实例化一个 XMLHttpRequest 对象
if (window.XMLHttpRequest) {
// 非IE
xhr = new XMLHttpRequest();
} else {
// IE
xhr = new ActiveXObject("Microsoft.XMLHTTP");
}
xhr.onreadystatechange = callbackHandler;
url = selectShow + ".html";
xhr.open("post", url, true);
xhr.send(null);
}
// this is the function that will repeatedly be called by our
// XMLHttpRequest object during the life cycle of request
function callbackHandler() {
if (xhr.readyState == 4) {
document.getElementById("divCharacters").innerHTML = xhr.responseText;
}
}
</script>
</head>
<body>
我们的第一个Ajax实例
<br></br>
选择一个名著：
<br>
<select onchange="updateCharacters();" id="selShow">
<option value=""></option>
<option value="xyj">西游记</option>
<option value="hlm">红楼梦</option>
<option value="shz">水浒传</option>
<option value="sgyy">三国演义</option>
</select>
<br></br>
返回，名著中主要任务：
<br>
<div id="divCharacters">
<select>
</select>
</div>
</body>
</html>