How to retrieve friends emails from Facebook in ASP.NET

Using FaceBookConnect i have retrieved friends namem id, pic but i not able to retieve friends emails, contact no. How to retrieve friends emails from Facebook..? in ASP.NET

protected void Page_Load(object sender, EventArgs e)
    {
        FaceBookConnect.API_Key = "API_Key";
        FaceBookConnect.API_Secret = "API_Secret";
        if (!IsPostBack)
        {
            string code = Request.QueryString["code"];
            if (!string.IsNullOrEmpty(code))
            {
                string data = FaceBookConnect.Fetch(code, "me/friends");
                FaceBookData facebookData = new JavaScriptSerializer().Deserialize<FaceBookData>(data);
                foreach (FaceBookUser user in facebookData.Data)
                {
                    user.PictureUrl = string.Format("https://graph.facebook.com/{0}/picture", user.Id);
                    user.Email = string.Format("https://graph.facebook.com/{0}?fields=email", user.Id);
                }
                gvFriends.DataSource = facebookData.Data;
                gvFriends.DataBind();
            }
        }
    }
    protected void btnFetch_Click(object sender, EventArgs e)
    {
        FaceBookConnect.Authorize("user_photos,email", Request.Url.AbsoluteUri.Split('?')[0]);
        //FaceBookConnect.Authorize("user_photos,friends_photos,email", Request.Url.AbsoluteUri);
    }

    public class FaceBookData
    {
        public List<FaceBookUser> Data { get; set; }
    }

    public class FaceBookUser
    {
            public string Id { get; set; }
            public string Name { get; set; }
            public string Email { get; set; }
            public string PictureUrl { get; set; }
    }