ZipFile Contents:
1. IdPlus1.mdb  Database
    Has a single form.
2. IdPlus2.mdb  Database
    A copy of IdPlus1.mdb with the IdPlus2 caption. 
3. IdPlus1_be.mdb Database
    The data source for IdPlus1/2 databases.
4. ReadMe.txt
    This file.
    
This combination of databasese illustrates that it
is safe to use the line:
ID = DMax("ID", "tName") + 1
without the risk of failure in the context shown.

There is also an option of supplying an invalid
value for the new ID. The value of 1 is chosen
because it is guaranteed to be invalid. The first
record in the recordset will always be 1 and the
option to supply an invalid ID is not executed for
the first record.

Suggested Method of Operation.
1. Place all three DBs in the same folder.

2. Open IdPlus1.mdb while holding down the shift
   key. Select the table and relink it.
   Close the DB.
   
3. Repeat for IdPlus2.mdb

4. Open IdPlus1.mdb and IdPlus2.mdb and display
   them alongside each other.
   
5. Add records to each DB in turn and notice the
   ID numbers that are generated.
   
Notes:
A. The 'Delete All Records' button allows you to 
   clear the records from the current DB. I have 
   left the Warning Message in as a reminder.
   If you go to the other DB you will notice that 
   when a record is selected and you try to select 
   data, the #Deleted symbol appears. You can still 
   add records on the DataEntry line at the bottom.

B. You can use the ReQuery button to clear the 
   display of Deleted Records, or to see all of the 
   records in the Source Table.
   
C. The 'Cause error' messagebox allows you to test
   what happens when an invalid ID is used. You
   can simply retry the save after getting an error.

Clive Williams 14Apr2010.    

