insert C# SQL

 string strSQL1;

            strSQL1 = "   insert into [tblcontrol_Comt] ( [SLNO],[Status],[Reason]) select " + t1 + ",'" + DropDownList4.SelectedItem + "','" + TB_Comment.Text + "'";

            strSQL = strSQL + strSQL1;

            //Response.Write(strSQL);

            //Response.End();

            SqlCommand cmd = new SqlCommand(strSQL, myConnection);

            cmd.CommandTimeout = 30000;

            cmd.CommandType = CommandType.Text;

            myConnection.Open();

            cmd.ExecuteNonQuery();

            myConnection.Close();