Hi, I want to delete parent record and related child record.I have used formula, same works fine for parent record deletion but am unable delete related child record.

Dan, The above code is working fine and am able to delete the parent record but i also want to delete related child records. so is it  possible to delete that by adding some extra piece of code?
and  api_delete the records with parameter rid  and unfortunately we are calling this button from parent table so we don't have that here. the only thing we have here is related record id, which is actually the key field of parent table.
so is there a way to get the rid of all child records those are related to parent record and then delete.