delete record

[abweb]

Good morning, i hope somebody can help me, i want to connect roudcube with my existent database of messages, i would like to add to roundcube a function that when i cancel a message from roundcube will make even a delete query on my table.

All the two table are in the same database, i tried to add the query in the move_delete.inc but don't function, the query to make is "delete from email where subject ='$subject' and username = '$user_id'"

How must to do?

Many thanks