title: Only accept numbers as GET-variable
body: <p>Hello,</p>
  
  <p>I want to allow only numbers in <code>$_GET</code> method. I use this is in pagination to secure</p>
  
  <p><code>$page = (isset($_GET['page']) &amp;&amp; is_numeric($_GET['page']) ? (int) $_GET['page'] : 1);</code></p>
  
  <p>If I enter special characters or alpha, it returns error</p>
  
  <p>This should not be possible:</p>
  
  <p><code>index.php?page=AA</code> and 
  <code>index.php?page='!@#$%^&amp;*()</code></p>
  
  <p>Only this:
  <code>index.php?page=1</code> or <code>2 ...</code></p>
  
  <p>Anyone has a solution for this? :) thanks in advance...</p>