title: Check file exists in variable
body: <p>Quite a simple one this I imagine.</p>
  
  <p>I'm submitting a form with text and images.</p>
  
  <p>I validate the text by checking the variable length !=0 etc.</p>
  
  <p>I need an effective way to check if the variable that should have a file within does.</p>
  
  <p>This is the code so far...</p>
  
  <pre><code>if(!$afterphoto){
      $form-&gt;setError($field, "After photo not entered");
  }
  </code></pre>
  
  <p>This doesn't seem to be working, what would be a better checker?</p>
  
  <p>Thanks.</p>