query problemer

PHP kode 

 <?php error_reporting(0);
  if (empty($_POST)) {
          include 'content/db/connect.php';
      $username = $_POST['username'];
      $email = $_POST['email'];
      $kodeord = $_POST['password'];
      
      if ($username && $email && $kode) {
          $ip= $_SERVER['REMOTE_ADDR'];
          $kode = md5(md5("4egedgdbvedsveghehghehsedhssdeui" . $kode . "dhndfghdbvswvdegbvfridikjdfrwssoi8u4"));
          
         mysql_query("INSERT INTO `users` (`id`, `brugernavn`, `kode`, `navn`, `efternavn`, `email`, `avatar`, `group`, `alder`, `hjemmeside`, `youtube`, `facebook`, `twitter`, `oprettet`, `last_login`, `ip`, `by`, `biografi`, `signatur`) VALUES ('', '$brugernavn', '$kodeord', '', '', '$email', '', '4', '', '', '', '', '', '', '', '', '$ip', '', '', ''))");
      }
  }?>

HTML kode 

 <form action="add.php" method="post"><h1>Opret admin bruger *</h1>
   <p>
   <label for="username">Admin navn *</label>
   </p>
   <p>
     <input type="text" name="username" />
     <label for="password"><br>
       Admin kode *</label>
     </p>
   <p>
     <input type="text" name="password" />
     </p>
   <p>
     <label for="email">Email 
       *</label>
   </p>
   <p>
     <input type="text" name="email" />
   </p>
   <p>
     <input type="submit" name="sub" value="Opret bruger" />
   </p>
 </form>