Delete File Attachment with API_EditRecord

Hi, thanks in advance, but what if I just wanted to make a button that deleted the file attachment on whichever record id I was viewing? for example -- I have a Table called 'Brady Bunch', and there are 6 rids so far -- each record id  has a picture of that child uploaded to it: Greg (rid_1), Marsha (rid_2), Peter (rid_3), Jan (rid_4), Bobby (rid_5), Cindy (rid_6).

Question 1:
I won't know which attachment I want to delete until I get on the actual record. How can I do this in the API script so the rid is more of a variable?

Question 2:
Where are you getting the update ID from?

Question 3:
When I save, it's telling me I need a 'Type'

Let me know when/if you have a moment?

Thanks!