if ($_POST['register']) {
  if (strstr($username,'\'')) { die('You cannot use \' in ur username, please try again'); }
  if (strstr($password,'\'')) { die('You cannot use \' in ur password, please try again'); }
  if (strstr($username,'\'')) { die('You cannot use \' in ur e-mail, please try again'); }
  $username = addslashes($_POST['username']);
  $password = addslashes($_POST['password']);
  $email = addslases($_POST['email']);