If the user is logged in you might want to changing your modify link in your footer from:
print qq!| <A HREF="$db_script_url?db=databasename&uid=$db_uid&modify_form=1&$db_key=*">Modify</A> ! if ($per_mod);
to:
print qq!| <A HREF="$db_script_url?db=databasename&uid=$db_uid&modify_form=1&ItemID=*">Modify</A> ! if ($per_mod);
Where ItemID is the actual name of the db_key. I believe that if you have the permissions setup for users to be able to only modify their own records this would take them directly to own their listings.
I tried this using on of my databases and it seems to work fine going directly to the listings of record this one user submitted.
If they can only have one record then this should open up the one record.
Give it a try and see if it works for you
You can also copy the link into your html_record to have it on the top of your page rather then in the footer menu.
This will perhaps give you more ideas of what to try if nothing else