What is the best way to get the ID of the inserted record?

I've tried changing the insert command to

rec = insert into Contract

[ .... etc. ]

but that fails on saving

I've also tried:

rec =  Contracts  [  Engagement == input.ID]

and

for each rec in  Contracts  [  Engagement == input.ID] {  }

both of which don't return an ID.

In the end, this seems to work:

with recid being what I want (I think) - but that seems a bit laborious.

Is there a cleaner way?

Thanks

Alex