(a) "Alteration" means (i) an unauthorized change in an instrument that purports to modify in any respect the obligation of a party; or (ii) an unauthorized addition of words or numbers or other change to an incomplete instrument relating to the obligation of a party.

(b) Except as provided in subsection (c) of this Code section, an alteration fraudulently made discharges a party whose obligation is affected by the alteration unless that party assents or is precluded from asserting the alteration. No other alteration discharges a party, and the instrument may be enforced according to its original terms.

(c) A payor bank or drawee paying a fraudulently altered instrument or a person taking it for value, in good faith and without notice of the alteration, may enforce rights with respect to the instrument (i) according to its original terms; or (ii) in the case of an incomplete instrument altered by unauthorized completion, according to its terms as completed.