private void btnTurktelekom_Click(object sender, EventArgs e)
        {
            this.Close();
            frmTLyukle frm = new frmTLyukle(Kartno);

            frm.Show();
        }
        private void btnVodafone_Click(object sender, EventArgs e)
        {
            this.Close();
            frmTLyukle frm = new frmTLyukle(Kartno);

            frm.Show();
        }