[nico_swd]

You can store the errors in sessions if you don't post the data to the same page.

PHP Code:


session_start();

if (/* username exists */)
{
    $_SESSION['errors'][] = 'Username taken';
}

// Go back to previous page and... 

if (is_array($_SESSION['errors']))
{
     echo 'Following errors ocurred: <br />';

     foreach ($_SESSION['errors'] AS $error)
     {
          echo '- '. $error .'<br />'. "\n";
     }
}