It depends on what you mean by increment the table row. If you are referring to incrementing it for insert then simply create the field as an auto-increment in MySQL and the database will auto-increment the field for you.
If you are simply trying to get to the next record in the table then post the current record_ID into a new field and add one to it. Then select the record where the record_id equals the new variable.
ok, lets say there are 2 rows. one that username. the username is john.
the next one is number. the number is 1. I want onclick 1 is added to the number. so after one click the row would be 2. after another the row would be 3