Okla. Stat. tit. 12, § 12-101: Extension of limitation - Part payment, acknowledgment or

new promise.

In any case founded on contract, when any part of the principal

or interest shall have been paid, or an acknowledgment of an

existing liability, debt or claim, or any promise to pay the same

shall have been made, an action may be brought in such case within

the period prescribed for the same, after such payment,

acknowledgment or promise; but such acknowledgment or promise must

be in writing, signed by the party to be charged thereby.