protected void btn_users_Click(object sender, EventArgs e)
        {
            MembershipUser CurrentUser = Membership.GetUser();
            Guid           UserId      = (Guid)CurrentUser.ProviderUserKey;
            Guid           otherId     = new Guid(ddl_users.SelectedValue);
            DataTable      dtt         = MessageBLL.GetAllMsgBw(UserId, otherId);

            gv_message.DataSource = dtt;
            //gv_message.DataKeyNames = new string[] { "Fk_FromId", "FK_ToId" };
            gv_message.DataBind();

            //dtt.PrimaryKey = new DataColumn[] { dtt.Columns["MessageId"], dtt.Columns["FK_FromId"] };
            //ViewState["Message"] = dtt;
        }
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                //MembershipUser CurrentUser = Membership.GetUser();
                //Guid UserId = (Guid)CurrentUser.ProviderUserKey;
                DataTable dt = MessageBLL.GetAllUsers();
                ddl_users.DataSource     = dt;
                ddl_users.DataTextField  = "UserName";
                ddl_users.DataValueField = "UserId";
                ddl_users.DataBind();


                if (Request.QueryString["messaging"] != null)
                {
                    Guid           otherId     = new Guid(Request.QueryString["messaging"]);
                    MembershipUser CurrentUser = Membership.GetUser();
                    Guid           UserId      = (Guid)CurrentUser.ProviderUserKey;
                    DataTable      dtt         = MessageBLL.GetAllMsgBw(UserId, otherId);
                    gv_message.DataSource = dtt;
                    gv_message.DataBind();
                }
            }
        }