title: Checking if request is post back in PHP
body: <p>How can I check if the request is a post back in PHP, is the below ok?</p>
  
  <pre><code>if (isset($_POST["submit"]))
  </code></pre>
  
  <p>where <code>submit</code> is the <code>name</code> of the <code>&lt;input type="submit" /&gt;</code></p>