原文地址：http://blog.sina.com.cn/s/blog_6513b5cf01013p5q.html
ajax.PHP
<head>
<Meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>
<script language="javascript">
function saveUserInfo()
{
//获取接受返回信息层
var msg = document.getElementByIdx_x("msg");
//获取表单对象和用户信息值
var f = document.user_info;
var userName = f.user_name.value;
var userAge = f.user_age.value;
var userSex = f.user_sex.value;
//接收表单的URL地址
var url = "./ajax_output.PHP";
//需要POST的值，把每个变量都通过&来联接
var postStr = "user_name="+ userName +"&user_age="+ userAge +"&user_sex="+ userSex;
//实例化Ajax
//var ajax = InitAjax();
var ajax = false;
//开始初始化XMLHttpRequest对象
if(window.XMLHttpRequest) { //Mozilla 浏览器
ajax = new XMLHttpRequest();
if (ajax.overrideMimeType) {//设置MiME类别
ajax.overrideMimeType("text/xml");
}
}
else if (window.ActiveXObject) { // IE浏览器
try {
ajax = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
ajax = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}
}
}
if (!ajax) { // 异常，创建对象实例失败
window.alert("不能创建XMLHttpRequest对象实例.");
return false;
}
//通过Post方式打开连接
ajax.open("POST",url,true);
//定义传输的文件HTTP头信息
ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
//发送POST数据
ajax.send(postStr);
//获取执行状态
ajax.onreadystatechange = function() {
//如果执行状态成功，那么就把返回信息写到指定的层里
if (ajax.readyState == 4 && ajax.status == 200) {
msg.innerHTML = ajax.responseText;
}
}
alert (userName);
}
</script>
<body >
<div id="msg"></div>
<form name="user_info" method="post" action="">
姓名：<input type="text" id="user_name"name="user_name" /><br />
年龄：<input type="text" name="user_age" /><br />
性别：<input type="text" name="user_sex" /><br />
<input type="button" value="提交表单" onClick="saveUserInfo()">
</form>
</body>
ajax_output.PHP
<?PHP
$username = $_POST['user_name'];
$userage = $_POST['user_age'];
$usersex = $_POST['user_sex'];
echo "$username <br>";
echo "$userage <br>";
echo "$usersex <br>";
$db = new MysqLi('localhost','root','123456','test');
if(!$db){
echo "连接失败！";
}
$db->query("set names utf8");
$query = "insert into userinfo(uname,uage,usex) values ('".$username."','".$userage."','".$usersex."')";
$result = $db->query($query);
if ($result){
echo "上传成功！";
}
else {
echo "失败！";
}
$db->close();
?>