url - How to get(extract) the values data parameter from the canvas page url after getting the Requests_ids

Question

I am able to get the value of Requests_ids by following way $requestid=$_GET['request_ids']; .

But I am unable to get the value of data variable which I passed to url like following way

FB.ui({method: 'apprequests',
        message: ms,
        max_recipients: 1,

        title: 'loveeeeeeeeee',
        new_style_message: true,           

        data: "Any value passed here" //I am passing few values to canvas page URL. 
    }, requestCallback);

How can i get this data values? Plz help me or suggest any other approach to pass the variables to canvas page url?