data exists but my program says, No data exists for the row/column C# : Please guide me how to resolve this. Thaaaaaaaaaaank youuuuuuuu

private void button3_Click(object sender, EventArgs e)
        {
            if (cn.State == ConnectionState.Closed)
            {
                cn.Open();
            }
            string student = "Select * From tbl_student";

            OleDbCommand loadstudent = new OleDbCommand(student, cn);
            loadstudent.Parameters.AddWithValue("@SId", textBox8.Text + "%");


            rd = loadstudent.ExecuteReader();
            if (rd.HasRows == true)
            {
                // ipapalabas ung labas
                while (rd.Read())
                {

                messageBox.Show("Oops sobra tama na ");

                }
            }
            else
            {
                MessageBox.Show("No record(s) found.");
            }
            cn.Close();




            if (cn.State == ConnectionState.Closed)
            {
                cn.Open();
            }
            string s = "Select * From Borrow";

            OleDbCommand sa = new OleDbCommand(s, cn);
            loadstudent.Parameters.AddWithValue("@SId", textBox8.Text + "%");


            rd = sa.ExecuteReader();
            if (Convert.ToInt32(rd["B_Quan"].ToString()) > 3)
            {
                MessageBox.Show("Oops sobra tama na ");
            }
            cn.Close();



            if (cn.State == ConnectionState.Closed) cn.Open();
            cmd = new OleDbCommand("Select * From Borrow", cn);
            rd = cmd.ExecuteReader();// ipapalitaw
            if (rd.HasRows == true)
            {
                // ipapalabas ung labas
                while (rd.Read())
                {
                    if (Convert.ToInt32(rd["B_Quan"].ToString()) > 3)
                        
                    {
                        MessageBox.Show("Oops sobra tama na ");
                        return;
                       
                    }
                }
            }


        }
    }
}