如何在Php中按下按钮导航到特定页面中的下一个div？

I want navigate to other div on button click in specific page . How can i do it by header() function or any other function in Php?

<form action="" method="post">
      <label for="name">Name:</label>
      <input type="text" name="name" value="" />
      <label for="email">Email:</label>
      <input type="text" name="email" value="" />

      <input type="submit" name="submit_request" class="submit_button" value="Sign up" />
</form>

<iframe name="my-iframe" src="about:blank"></iframe>
    <div id="text_submit" class="text-success">
        <p class="text-center">
            THANK YOU FOR SIGNUP WITH US.
        YOUR FORM SUBMITTED SUCCESSFULLY!
        </p>
    </div>

PHP

<?php
    if(isset($_POST['submit_request']))
    {
        $name= $_POST["fn"];
        $email= $_POST["ln"];

       header("location:my-iframe") // this is a div

    }

to redirect to other page you must use header() here is the syntax:

header('Location: http://www.google.com/');