title: Using hidden value instead of $_GET or $_REQUEST
body: <p>I have been using hidden values for forms.  </p>
  
  <p>Example: </p>
  
  <pre><code> &lt;form method="post" action="page.php"&gt;
   &lt;input type="text" name="name""
   &lt;input type="hidden" name="book_id" value="$bookid"&gt;
   &lt;input type="button"&gt;
   &lt;/form&gt;
  </code></pre>
  
  <p><code>$bookid</code> is the <code>$_GET</code> value for <code>book.php?id=34324</code></p>
  
  <p>So instead of doing <code>page.php?id=$bookid</code> I am using <code>$bookid</code> in hidden field. </p>
  
  <p>My Question:  Is it harmful if i use hidden values vs using <code>$GET</code> or <code>$POST</code> in the form action?</p>