使用iframe实现无刷新提交表单

<?php  

header("Content-type: text/html; charset=utf8");  

?>  

<iframe name="testIframeName" style="display:none;"></iframe>  

<form target="testIframeName" method="post" action="formAction.php">  

<input type="text" name="username"/>  

<input type="password" name="password"/>  

<input type="submit" value=" 提 交 " />  
</form>

<?php  

$user=$_POST['username'];

$pass=$_POST['password'];

if($user=='an'&&$pass=='123')

echo "<script>alert(登录成功....');</script>";  

?>