Why Oracle Update Sql Update not work when use Where with Params

Hello all

This is a snapshot of a copy form SQL Monitor that create in the
runtime.
My question is why it is not update?
Please help if you can
Sincerely yours

Tin Le

SQL Prepare: ORACLE - Update SCOTT.ADT
Set PatType = :1,
AdmitDate = :2,DisChargeDate = :3
Where (BillingNumber = :4 )
AND (ChartVolume = :5 )

SQL Execute: ORACLE - Update SCOTT.ADT
Set PatType = ?,
AdmitDate = ?,DisChargeDate = ?
Where (BillingNumber = ? )
AND (ChartVolume = ? )

176     16:01:23  SQL Data In: ORACLE - Param = 2, Name = , Type =
fldTIMESTAMP, Precision = 1, Scale = 0, Data = 5/19/1995 0:0:0:0
177     16:01:23  SQL Data In: ORACLE - Param = 3, Name = , Type =
fldTIMESTAMP, Precision = 1, Scale = 0, Data = 5/19/1995 0:0:0:0
178     16:01:23  SQL Data In: ORACLE - Param = 4, Name = , Type =
fldZSTRING, Precision = 10, Scale = 0, Data = 8900472591
179     16:01:23  SQL Data In: ORACLE - Param = 5, Name = , Type =
fldZSTRING, Precision = 1, Scale = 0, Data = *
180     16:01:23  SQL Execute: ORACLE - Update SCOTT.ADT
Set PatType = ?,
AdmitDate = ?,DisChargeDate = ?
Where (BillingNumber = ? )
AND (ChartVolume = ? )