ajax 级联动菜单代码
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>ajax2级联动菜单演示</title>
<script language="javascript">
var http_request = false;
function send_request(url) { //初始化，指定处理函数，发送请求的函数
http_request = false;
//开始初始化XMLHttpRequest对象
if (window.XMLHttpRequest) { //Mozilla浏览器
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) { //设置MIME类别
http_request.overrideMimeType("text/xml");
}
} else if (window.ActiveXObject) { //IE浏览器
try {
http_request = new ActiveXObject("Msxml2.XMLHttp");
} catch (e) {
try {
http_request = new ActiveXobject("Microsoft.XMLHttp");
} catch (e) {}
}
}
if (!http_request) { //异常，创建对象实例失败
window.alert("创建XMLHttp对象失败！");
return false;
}
http_request.onreadystatechange = processrequest;
//确定发送请求方式，URL，及是否同步执行下段代码
http_request.open("GET", url, true);
http_request.send(null);
}
//处理返回信息的函数
function processrequest() {
if (http_request.readyState == 4) { //判断对象状态
if (http_request.status == 200) { //信息已成功返回，开始处理信息
document.getElementById(reobj).innerHTML = http_request.responseText;
} else { //页面不正常
alert("您所请求的页面不正常！");
}
}
}
function getclass(obj) {
var pid = document.form1.select1.value;
document.getElementById(obj).innerHTML = "<option>loading...</option>";
send_request('doclass.php?pid=' + pid);
reobj = obj;
}</script>
</head>
<body>
<form name="form1">
<select name="select1" id="class1" style="width:100;" onChange="getclass('class2');">
<option selected="selected"></option>
<option value="1">大类1</option>
<option value="2">大类2</option>
</select>
<select name="select2"id="class2" style="width:100;">
</select>
</form>
<?php
header("Content-type: text/html;charset=GBK"); //输出编码,避免中文乱码
$pid = $_GET['pid'];
$db = mysql_connect("localhost", "root", "7529639"); //创建数据库连接
mysql_query("set names 'GBK'");
mysql_select_db("menuclass");
$sql = "select classname from menu where parentid=" . $pid . "";
$result = mysql_query($sql);
//循环列出选项
while ($rows = mysql_fetch_array($result)) {
echo '<option>';
echo $rows['classname'];
echo "</option>n";
}
?></body>
</html>
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