Okla. Stat. tit. 12, § 12-2611

A. Subject to subsection B of this section, the court shall

exercise control over the manner and order of interrogating

witnesses and presenting evidence so as to:

1. Make the interrogation and presentation effective for the

ascertainment of the truth;

2. Avoid needless consumption of time; and

3. Protect witnesses from harassment or undue embarrassment.

B. Any party to a civil action or proceeding may compel any

adverse party or person, or any agent, servant or employee of such

party or person, for whose benefit such action or proceeding is

instituted, prosecuted or defended, to testify as a witness, at the

trial, or by deposition, in the same manner and subject to the same

rules as other witnesses, provided that any such adverse party, or

the adverse party’s agent, servant or employee called as a witness

by the opposing party shall be deemed a hostile witness and may be

cross-examined by the party calling the witness to the same extent

as any opposition witness.

C. Cross-examination shall be limited to the subject matter of

the direct examination and matters affecting the credibility of the

witness. The court may permit inquiry into additional matters as if

on direct examination.

D. Leading questions should not be used on the direct

examination of a witness except as may be necessary to develop the

witness’s testimony. Leading questions should ordinarily be

permitted on cross-examination. When a party calls a hostile

witness, an adverse party, or a witness identified with an adverse

party, leading questions may be used on direct examination.