I'm currently using a simple "Auto enter Serial number", but would like to use a more secure PrimaryID.(As in the article by captkurt!). How can I replace the old ID and still keep the relationships.

Peter

What I suggest you do is:

1. Backup the whole file set before you start.

2. Create the new ID number series in an additional text field in your main file (eg populate it according to a calculation, using the Replace with calculated result option).

3. Create a new text field in your related file(s), define it as a lookup based on a relationship back to your mainfile (matching the existing serial number fields) then run a reloolup to bring all the IDs across.

4. Run a 'Replace with calculated result' procedure on the serial number field in the main file with a formula which references the new ID field to copy its value over the serial (this will break the relationship/s for the moment...)

5. Repeat step 4 in each related file (this will restore the relationships, but based on the ID not the serial).

7. Delete the additional ID fields which were created at steps 2 and 3.

8. Save each of the files with the 'Save As...' - 'Compressed Copy Smaller' option, placing them in a new solution directory (keeping the names the same as the originals).

9. Archive the old files and backups and test thoroughly to make sure the files are working to specifications with their new IDs!

Thanks

It works perfectly!

Peter