There is a system error in the code... but i not able to identify it... the store procedure is working fine... but don't know why still got error...


DataSet ds;
string dbConn ="Initial Catalog=Northwind;Data Source=THLEE;Integrated Security=SSPI;";
SqlParameter [] arParms = new SqlParameter[2];
arParms[0] = new SqlParameter("@MedicIc_No", SqlDbType.Int, 10,"Customer_Ic_No");
arParms[0].Direction = ParameterDirection.Input;
arParms[0].Value = txtMedicIC.Text;

arParms[1] = new SqlParameter("@Allergy", SqlDbType.Text, 40,"Customer_Allergy");
arParms[1].Direction = ParameterDirection.Output;

using (SqlConnection conn = new SqlConnection(dbConn) )
{
    conn.Open();
    using (SqlTransaction trans = conn.BeginTransaction())
    {

    ds = SqlHelper.ExecuteDataset(trans, commandType.StoredProcedure, "usp_SearchCustomerMedic", arParms);
    txtMedicAllergy.Text = arParms[2].Value.ToString();
    trans.Commit();
    }
    conn.Close();
    }