How do I automatically delete records that contain a relationship

Here's the problem,

I have 2 tables

Tabel 1 contains the names of people

PersonID - AutoInc / PrimaryKey
PersonName

Table 2 contains Wdigets with the field PersonID being the relationship to people

WidgetID AutoInc/PrimaryKey
PersonID (relationship with Table1)
WidgetName

OK Now the challenge; Just say a person with the name David has 20 entries in the Widget Table and i now want to delete the perosn from the database, Easy enough to delete the person from the table but then I have all these entries left in the Widgets table with a relationship to David that does not exist.

How do I update or delete fields containing to each other in 2 databases?

Thanks