Widhdrawing an 'Offer' of a DRAW

What if I Offer a DRAW, and the Opponent does NOT accept it for the next 2 moves, after which I see myself in an advantageous position and now I feel like withdrawing from the DRAW Offer?

Q 1 - Can you really have a couple of moves with an 'Open Draw' Offer?

Q 2- If the answer to Q 1 is 'YES', then is it possible to to withdraw the DRAW Offer?

You draw offer is only good for your opponents next move--there is no "open" draw offer. Once he moves he has declined your offer and can not force a draw unless

1) The position forces it ( three time repetition/stalemate/lack of mating material)

2) He offers you a draw

3) You offer him a draw (again)

Tanx Mate. That helps a lot :)

I was worried for a minute there. :)