Friends, I would like some help with a code that allows me to run an append query only if a specific field is not already stored into another table.

Example.
I add a new customer to my database using table1.
I type his SSN. The code should check if this SSN is already present in another table (table2). If yes, so the code should skip the append query and just update any modified record included the SSN.

If not, the code should run the append query.

All this should be done in the background while working in a form with its recors source to the table1.

Can anyone help me? Thanks.