sample.js

    FB.provide('UIServer.Methods', {
      'permissions.request': {
        size : { width: 575, height: 240 },
        url : 'connect/uiserver.php',
        transform : function(call) {
            if (call.params.display == 'dialog') {
              call.params.display = 'iframe';
              call.params.channel = FB.UIServer._xdChannelHandler(
                  call.id,
                  'parent.parent'
                );
              call.params.cancel = FB.UIServer._xdNextHandler(call.cb, call.id, 'parent.parent', true );
              call.params.next = FB.UIServer._xdResult(call.cb, call.id, 'parent.parent', false );
            }
            return call;
          }
      }
    });