Sec. 413. (a) The acceptor of a draft is obliged to pay the draft:
(1) according to its terms at the time it was accepted, even though the acceptance states that the draft is payable "as originally drawn" or equivalent terms;
(2) if the acceptance varies the terms of the draft, according to the terms of the draft as varied; or
(3) if the acceptance is of a draft that is an incomplete instrument, according to its terms when completed, to the extent stated in IC 26-1-3.1-115 and IC 26-1-3.1-407.
The obligation is owed to a person entitled to enforce the draft or to the drawer or an endorser who paid the draft under IC 26-1-3.1-414 or IC 26-1-3.1-415.
(b) If the certification of a check or other acceptance of a draft states the amount certified or accepted, the obligation of the acceptor is that amount. If:
(1) the certification or acceptance does not state an amount;
(2) the amount of the instrument is subsequently raised; and
(3) the instrument is then negotiated to a holder in due course;
the obligation of the acceptor is the amount of the instrument at the time it was taken by the holder in due course.