title: Problem with require_once in a hello world facebook app
body: <p>Im new to developing facebook apps.I have the following issue and would be glad if someone could help.</p>
  
  <p>I have registered my app on facebook and uploaded the code and php client library to the hosting server. If i use the code below then everything works fine.</p>
  
  <pre><code>&lt;?php
  
  require_once('./facebook/php/facebook.php');
  
  /* initialize the facebook API with your application API Key
    and Secret */
  $facebook = new Facebook("&lt;my_api_key&gt;","&lt;my_secret_key&gt;");
  
  $user = $facebook-&gt;require_login();
  
  echo "&lt;p&gt;Your User ID is: $user&lt;/p&gt;";
  
  echo "&lt;p&gt;Your name is: &lt;fb:name uid=\"$user\" useyou=\"false\"/&gt;&lt;/p&gt;";
  
  echo "&lt;p&gt;You have several friends: &lt;/p&gt;";
  $friends = $facebook-&gt;api_client-&gt;friends_get();
  echo "&lt;ul&gt;";
  
  foreach ($friends as $friend)  {
  echo "&lt;li&gt;&lt;fb:name uid=\"$friend\" useyou=\"false\" /&gt;&lt;/li&gt;"; 
  }
  echo "&lt;/ul&gt;";
  
  /* Echo some information that will
    help us see what's going on with the Facebook API: */
  echo "&lt;pre&gt;Debug:" . print_r($facebook,true) . "&lt;/pre&gt;";
  
  
  ?&gt;
  </code></pre>
  
  <p>But, if i divide the code into two files as follows then i just get a blank canvas when i navigate to <a href="http://apps.facebook.com/myapp" rel="nofollow noreferrer">http://apps.facebook.com/myapp</a></p>
  
  <p><strong>appinclude.php</strong></p>
  
  <pre><code>&lt;?php
  require_once('./facebook/php/facebook.php');
  
  /* initialize the facebook API with application API Key
    and Secret */
  $facebook = new Facebook("&lt;my_api_key&gt;","&lt;my_secret_key&gt;");
  
  $user = $facebook-&gt;require_login();
  
  ?&gt;
  </code></pre>
  
  <p><strong>index.php</strong></p>
  
  <pre><code>&lt;?php
  
  require_once('./appinclude.php');
  
  echo "&lt;p&gt;Your User ID is: $user&lt;/p&gt;";
  
  echo "&lt;p&gt;Your name is: &lt;fb:name uid=\"$user\" useyou=\"false\"/&gt;&lt;/p&gt;";
  
  echo "&lt;p&gt;You have several friends: &lt;/p&gt;";
  $friends = $facebook-&gt;api_client-&gt;friends_get();
  echo "&lt;ul&gt;";
  
  foreach ($friends as $friend)  {
  echo "&lt;li&gt;&lt;fb:name uid=\"$friend\" useyou=\"false\" /&gt;&lt;/li&gt;"; 
  }
  echo "&lt;/ul&gt;";
  
  /* Echo some information that will 
    help us see what's going on with the Facebook API: */
  echo "&lt;pre&gt;Debug:" . print_r($facebook,true) . "&lt;/pre&gt;";
  
  ?&gt;
  </code></pre>
  
  <p>Any way to fix this ?</p>
  
  <p>Thank You.</p>