1.新建 a.html
<!doctype html> <html> <head> <meta charset='utf-8'> <title>iframe式ajax调用</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>