Update not commit in a function

Question

Hi,
I created a function that does an update. The SQL statement works fine on its own. But when I put this SQL statement in a function and used a .NET application to call this function, it didn't update the record. I even put the commit statement after the update but still no go. Any helps would be greatly appreciated.
Here is the Function:
create or replace
FUNCTION UPD_RENEWALDATE(CUST IN VARCHAR2, LOGON IN VARCHAR2, RNWL_DT IN DATE) RETURN INTEGER
IS
BEGIN
UPDATE "Customer" set
"RenewalDate" = TO_DATE(TO_CHAR(TRUNC(RNWL_DT) ,'MM/DD/YYYY'), 'MM/DD/YYYY'),
"ModifiedOn" = TRUNC(SYSDATE),
"ModifiedBy" = LOGON
WHERE "CustomerNumber" = CUST AND "IsCurrent" = 'Y';
COMMIT;
RETURN 1;
END;

Answer 1

Thanks for the suggestion. But I have codes in the .NET application that query the same table with the same input parms(CUST) and it returned the correct value. So if the CUST parm is not passing correctly, it should happened to all my read functions/SProc. I even hardcoded the value in parm1.value='123456' but it still won't update. CUST is varchar2 in the table but the content is numeric...weired.
Any help would be greatly appreciated. Here is the function to query the customer out before the update and it worked fine. The Update SProc is very similar to this but won't work.
Public Shared Function GetCustomer(ByVal CUST As String) As DataTable
Dim cnn As Oracle.DataAccess.Client.OracleConnection = New Oracle.DataAccess.Client.OracleConnection(ConfigurationSettings.AppSettings("ConnectionString"))
Dim cmd As Oracle.DataAccess.Client.OracleCommand = New Oracle.DataAccess.Client.OracleCommand("Get_Customer", cnn)
cmd.CommandType = CommandType.StoredProcedure
Dim p_refcursor As Oracle.DataAccess.Client.OracleParameter = New Oracle.DataAccess.Client.OracleParameter
p_refcursor.OracleDbType = OracleDbType.RefCursor
p_refcursor.Direction = ParameterDirection.ReturnValue
cmd.Parameters.Add(p_refcursor)
Dim Parm1 As Oracle.DataAccess.Client.OracleParameter = New Oracle.DataAccess.Client.OracleParameter
Parm1 = cmd.Parameters.Add(":CUST", OracleDbType.Varchar2, 7, CUST, ParameterDirection.Input)
Dim da As Oracle.DataAccess.Client.OracleDataAdapter = New Oracle.DataAccess.Client.OracleDataAdapter(cmd)
Dim ds As DataSet = New DataSet
Try
da.Fill(ds)
Return ds.Tables(0)
Catch
'Response.Write(vbCrLf & ex.ToString & vbCrLf)
Finally
da.Dispose()
p_refcursor.Dispose()
cmd.Dispose()
End Try
End Function