Android - read and delete new SMS of a specific sender only

Question

I'm trying to write the next function:

1) Send SMS to a service number

2) Read the response SMS content (the service's auto sent-back message that tells me if I succeed/failed to turn on the service)

3) Delete the service's auto-sent SMS

I know how to do the first step, and I should be able to do the second with both:

getMessageBody ()

getOriginatingAddress ()

but:

1) how can I refer the last incoming message to use the above functions?

2) how can I delete that specific message?

Thanks, John