Username not displayed in Facebook Hello world application

I am new to creating a facebook application and hence started out with a simple Hello World Application. But When I try to display my Name, it is not displayed.

This is my code:

 <?php
   require_once 'facebook.php';

   $api_key = 'mykey';
   $secret = 'mysecretkey';
   $facebook = new Facebook($api_key, $secret);
   $user = $facebook->require_login();

   $fbml      = "<h2>Hello world, my name is <fb:name uid='<?php echo $fb_user;?>'   useyou='false' />,"
       . "welcome to my first facebook application!</h2>";
   echo $fbml;
?>

The output in my facebook app is,

     Hello world,my name is,welcome to my first facebook application!

My name is missing here.

And If I add the code given below,to display the friend's list,

 $friends = $facebook->api_client->friends_get();
 echo "<pre>Friends:" . print_r($friends, true). "</pre>";

I get the error message,

 Warning: fopen() [function.fopen]: php_network_getaddresses: getaddrinfo failed:
 No such host is known. 
 in C:\Documents and Settings\2561开发者_如何学运维48\My Documents\ide\xampplite\htdocs\facebookApp\facebookapi_php5_restlib.php on line 1755

 Warning: fopen(http://api.facebook.com/restserver.php) [function.fopen]:
 failed to open stream: php_network_getaddresses: getaddrinfo failed: 
 No such host is known. in C:\Documents and Settings\256148\My Documents\ide\xampplite\htdocs\facebookApp\facebookapi_php5_restlib.php on line 1755

Please guide me.

I have found a solution for my problem. I had to set the connect url in the application setting to my canvas callback url and created a cross domain communication channel file as given in this tutorial. This tutorial is really very helpful and explains in detail about creating a simple facebook app.

But still I get the Network error when I use $facebook->api_client->friends_get();

FBML Facebook Application

First, try using the following code for authentication process (applogin.php):

<?php
require_once "facebook.php";
require_once "config.php";

$facebook = new Facebook(array(
    'appId'  => FB_APP_ID,
    'secret' => FB_API_SECRET,
    'cookie' => true
));

$session = $facebook->getSession();

$params = array(
        'canvas'     => 1,
        'fbconnect'  => 0,
        'next'       => URL_CANVAS,
        'cancel_url' => 'http://www.facebook.com/',
        'req_perms'  => 'publish_stream, status_update, offline_acces'
    );
$login_url = $facebook->getLoginUrl($params);

// if not logged in, redirec to login page
if (!$session) {
    echo '<fb:redirect url="' . $login_url . '" />';
    exit;
} else {
    try {
        $uid = $facebook->getUser();
        $me  = $facebook->api('/me');
        $access_token = $session['access_token'];
    } catch (FacebookApiException $e) {
        echo 'Error';
        exit;
    }
}
?>

Here's the config.php:

<?php
// Facebook 
    define('FB_APP_ID', '');
    define('FB_API_SECRET', '');
    define('URL_CANVAS', 'http://apps.facebook.com/YOURAPP/');
    define('URL_CALLBACK', 'http://FB.YOURCALLBACKURL.COM/YOURAPP/');
?>

And finally your index.php

<?php
require_once dirname(__FILE__) . "/applogin.php";

// using Graph API
echo $me['name'];
?>
<!--// some FBML //-->
<fb:bookmark />
<h2>Hello world, my name is fb:name uid='<?php echo $uid;?>'   useyou='false' /> 
welcome to my first facebook application!</h2>

Hope this will help you write your own Facebook application.