Send $forum_id when submit

Question

I have created an script , and I want to use to replace posting.php with it on phpbb3

The script its a form, with action="application"

When i click on "new topic" i have redirected to submit.php?mode=post&f=3 instead of posting.php?mode=post&f=3

and then in submit.php I have and html with fields, and a submit button

The problem is that when performs the action="application.php" I need to give the forum id to that php when click on submit.

any ideas?

UPdaTE

this is my app.html:

<!-- INCLUDE overall_header.html -->
    <!-- <h2> Form Submission </h2>
      <div class="panel">
      <div class="inner"><span class="corners-top"><span></span></span> -->
        <form  method="post" action="application.php" accept-charset="utf-8" >
            $id = htmlspecialchars($_GET['f']);
            <input type="hidden" name="forum_id" value="<?php echo $id; ?>"/>
            <span class="corners-top"><span></span></span>
            <label>Agregar Url De La Pelicula</label><br>
            <input id="link" name="link" type="text" value="http://www.filmaffinity.com/es/film628461.html" size="100" maxlength="100">
            <fieldset class="submit-buttons">
                <input value="Submit" class="button2" type="submit">
           </fieldset>

       </form>

     <!-- <span class="corners-bottom"><span></span></span></div>
   </div> -->
      <!-- INCLUDE overall_footer.html -->

this is my submit.php:

http://pastebin.com/unjSNwMT

and this my application.php:

Answer 1

Use a hidden input field.

<input type="hidden" name="fourm_id", value="<?php echo $_GET['f']; ?>"/>

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