Sorry, this is probably a noddy question (again). I've not been working for Xataface for soooo long that what skillz I had are long gone

I have a table (lets say table1) with a relationship (1 to many) with another table (table2). In terms of adding stuff to it, that all works fine (using the grid widget). However, when I delete the entry from table1, the relationship data still remains in table2. How can I get it to delete the table1 data and the table2 data when in one go.
I've a feeling I've asked this before, but can't seem to find the post.
Cheers
Paul