Start simple and build:

1. Create a table with two columns:

POID
PODate

2. Create a form from the table using the form wizard.

3. Change the two textbox names on the form to:

txtPOID
txtPODate

txtPOID’s control source is POID, txtPODate’s control source is PODate.

4. Set txtPOID’s Enabled property to No.

5. Paste this behind the form:

Private Sub Form_BeforeInsert(Cancel As Integer)

   Dim strID As String
   Dim lngID As Long

   lngID = Nz(DMax("[POID]", "tblPurchaseOrders") + 1, 1)

   Select Case lngID
      Case 60000
         Me![POID] = 500000
         Me![txtPOID].Requery
      Case 6000
         Me![POID] = 50000
         Me![txtPOID].Requery
     Case Else
         Me![POID] = lngID
         Me![txtPOID].Requery
     End Select

End Sub

I added the Nz function so the code will run if the table is empty.

6. Open the form.

7. Start typing a date. The POID should fill in for you.

8. Close the form.

9. Add the following record to the table: 5999, 1/1/2001

10. Open the form

11. Start typing a date. The POID should change to 50000.

Regards,

Bob