PHP Headers Login System

Headers Login System

<?
$auth = false;
$members = ".members";
if (isset( $PHP_AUTH_USER ) && isset($PHP_AUTH_PW) && is_file($members)) { 
  $data = file($members);
  foreach($data as $show) {
    $show = trim($show);
    $part = explode("|",$show);
    if ($part[0] == $PHP_AUTH_USER && $part[1] == $PHP_AUTH_PW) {
      $auth = true;
      break;
    }
  }
}
if (!$auth) { 
  header( 'WWW-Authenticate: Basic realm="Private"' ); 
  header( 'HTTP/1.0 401 Unauthorized' ); 
  echo 'Authorization Required.'; 
  exit; 
}
else { 
  echo '<P>Your are authorized!</A></P>'; 
}
?>