I understand from your words is that you want to notify the end user that this object can't be deleted because there exists certain related objects in the system.
For this you should perform some queries on the related tables before you call the delete method.
Something like:
SELECT Count(*) FROM someTable WHERE someFkField = xyz
Which can be performed with using the GetScalar() method.
If all the GetScalar() calls to the releated tables return Zero, then you should proceed with the delete, otherwise you should report which related tables hod some records that reference the main object to be deleted.
Otherwise if you want to save youself all this hassel, you may just delete the record and handle the exception thrown from the database, and report it back to the user in a user friendly message. (Which I normaly do to save several database calls).