protected void grvContact_RowDeleting(object sender, GridViewDeleteEventArgs e)
        {
            int      Id  = Convert.ToInt32(grvContact.DataKeys[e.RowIndex].Value);
            BContact obj = new BContact();

            if (obj.Delete(Id))
            {
                lblThongBao2.Text = "BẠN ĐÃ XÓA THÀNH CÔNG DANH BẠ!";
            }
            grvContact_Load();
        }
        protected void btnXoa_Click(object sender, EventArgs e)
        {
            BContact obj = new BContact();

            foreach (GridViewRow row in grvContact.Rows)
            {
                CheckBox checkbox = (CheckBox)row.FindControl("MyCheckBox");

                if (checkbox.Checked == true)
                {
                    int Id = Convert.ToInt32(grvContact.DataKeys[row.RowIndex].Value);
                    obj.Delete(Id);
                    lblThongBao2.Text = "BẠN ĐÃ XÓA THÀNH CÔNG DANH BẠ!";
                }
            }
            grvContact_Load();
        }