Getting information about the current record only

How do I limit my results to only the current record? I have an ACCESS form that I would like to use a button to run an update query to automatically create a pin number based on first name, last name and the last four of SSN. Once the form is filled out, the data entry clerk can click the button to run the query to generate the pin. When I run the query, it updates all of the records in the table. I would like to restrict it to the current record only.

You need to have a unique value on the records. You did not give information on the records so I cannot give exact help.

You could try using the criteria you use to create the pin to limit the update.