SqlCommand command = conn.CreateCommand();
        command.CommandText = "select Test from PrescTest pt, Prescription p where pt.idPresc=p.idPresc";
        conn.Open();

        SqlDataReader dr2 = command.ExecuteReader();
        try
        {
            if (dr2.HasRows)
            {
                string Tests ="";
                while (dr2.Read())
                {
                    // get the results of column "Test"
                    Tests += dr2["Test"].ToString() + System.Environment.NewLine;
                }
                TextBox15.Text = Tests.Trim();
                conn.Close();
            }
        }