!doctype html>
html>
head>
meta charset='utf-8'>
title>iframe式ajax調用/title>
/head>
body>
form action='b.php' method='post' name='' id='' target='formTarget'>
input type='text' name='username' id='' placeholder='' value='' />
input type='submit' name='' value='提交' />
span id='msg'>/span>
/form>
iframe src='' name='formTarget' id='formTarget' style='display:none'>/iframe>
/body>
/html>

?php
echo "
script>
parent.document.getElementById('msg').innerHTML = 'iframe式ajax調用成功!';
alert('您輸入的是：{$_POST['username']}');
window.setTimeout(function(){
parent.window.location.reload();
},3000);
/script>