title: Wordpress add_menu_page include a php page from theme directory
body: <p>I have added some custom tables to a wordpress and trying to add wp-admin section to manage them. By using following code I have successfully added a menu item in wp-admin but I'm unable to call the php page that resides into my theme folder</p>
  
  <pre><code>add_menu_page('Private Messages', 'Private Messages', 'manage_options',
                'message_admin', 'message-admin.php',
                 get_bloginfo('stylesheet_directory').'/style/images/message.png');
  </code></pre>
  
  <p>in error_log it gives me this error</p>
  
  <blockquote>
    <p>PHP Warning:  call_user_func_array() expects parameter 1 to be a valid callback, function 'message-admin.php' not found or invalid function name in /var/www/idon.dev/wp-includes/plugin.php on line 470, referer: <a href="http://idon.dev/wp-admin/admin.php?page=message_admin" rel="nofollow">http://idon.dev/wp-admin/admin.php?page=message_admin</a></p>
  </blockquote>