title: isset vs empty vs is_null
body: <p>I'm trying to write a script that when a user uploads a file and does not enter a name an error is returned. I've tried using is_null, empty, and isset and they all do not work. Eg, below, is_null returns an error even when a name is entered. Can anyone help?</p>
  
  <pre><code>$caption = $_REQUEST[$name_input_name];
  
  if(is_null($caption)) {
      $file-&gt;error = 'Please Enter a Title';
      return false;
  }
  </code></pre>