Facebook : Invite Page

<?php
//?fb_force_mode=fbml
require_once '../facebook.php';
$api_key = '8b68ebaa2353e83cd906b246###';
$secret = '8d4348f4bbfaa176b0c29e364f###';

// Names and images
$app_name = "Map App";
$app_url = "map_app";

// Assumes application is at http://apps.facebook.com/app-url/
$app_image = "Application image URL";
$invite_href = "invite.php?fb_force_mode=fbml";

// Rename this as needed require_once 'facebook.php';
$facebook = new Facebook($api_key, $secret);
$facebook->require_frame();
$user = $facebook->require_login();

if(isset($_POST["ids"])) {
  echo "<center>Thank you for inviting ".sizeof($_POST["ids"])." of your friends on <b><a href=\"http://apps.facebook.com/".$app_url."/\">".$app_name."</a></b>.<br><br>\n";
  echo "<h2><a href=\"http://apps.facebook.com/".$app_url."/\">Click here to return to ".$app_name."</a>.</h2></center>";
} else {
  // Retrieve array of friends who've already added the app.
  $fql = 'SELECT uid FROM user WHERE uid IN (SELECT uid2 FROM friend WHERE uid1='.$user.') AND is_app_user = 1';
  $_friends = $facebook->api_client->fql_query($fql);

  // Extract the user ID's returned in the FQL request into a new array.
  $friends = array();

  if (is_array($_friends) && count($_friends)) {
    foreach ($_friends as $friend) { $friends[] = $friend['uid']; } }

  // Convert the array of friends into a comma-delimeted string.
  $friends = implode(',', $friends);

  // Prepare the invitation text that all invited users will receive.
  $content = "<fb:name uid=\"".$user."\" firstnameonly=\"true\" shownetwork=\"false\"/> has started using <a href=\"http://apps.facebook.com/".$app_url."/\">".$app_name."</a> and thought it's <u>so cool even you should try it out</u>!\n".
             "<fb:req-choice url=\"".$facebook->get_add_url()."\" label=\"Add ".$app_name." to your profile\"/>";
?>
  <fb:request-form action="<? echo $invite_href; ?>" method="post" type="<? echo $app_name; ?>" content="<? echo htmlentities($content); ?>" image="<? echo $app_image; ?>">
    <fb:multi-friend-selector actiontext="Here are your friends who don't have <? echo $app_name; ?> yet. Invite whoever you want -it's free!" exclude_ids="<? echo $friends; ?>" />
  </fb:request-form>
<?
}
?>