title: getimagesize() warning - filename cannot be empty
body: <p>I've got a formular in which users should upload an image with a specific dimension and type.
  When I select an image and click on the submit button, a warning comes up: </p>
  
  <blockquote>
    <p>Warning: getimagesize() [function.getimagesize]: Filename cannot be empty in xxx.php on line 5</p>
  </blockquote>
  
  <p>The code to check dimensions and type isn't necassary for this issue.</p>
  
  <pre><code>&lt;!-- language: lang-php --&gt;
  &lt;?php
      if (isset($_POST["submit"])) {
          list($width, $height, $type, $attr) = getimagesize($_FILES["image"]["name"]);       
      } else { ?&gt;
  
      &lt;form action="#" method="post" enctype="multipart/form-data"&gt;
          &lt;input type="file" name="image" /&gt;
          &lt;input type="submit" name="submit" /&gt;
      &lt;/form&gt;             
  &lt;?php } ?&gt;
  </code></pre>