Section 99

If a witness, upon cross-examination as to a previous oral statement made by him relevant to matters in question in the suit or proceeding in which he is cross-examined and inconsistent with his present testimony, does not distinctly admit that he made such statement, proof may be given that he did in fact make it; but before proof can be given, the circumstances of the supposed statement, sufficient to designate the particular occasion, shall be mentioned to the witness, and he shall be asked whether or not he made such statement.

Questions lawful in cross-examination