The principal question raised by this appeal relates to the trial court’s exclusion of certain evidence and is to be determined according to the law of the forum. Restatement, Conflict of Laws § 597. Under the undisputed facts appearing of record, which contain neither averment nor proof of fraud, accident or mistake in the making of the written contract whereon the suit is based, the learned trial judge very properly overruled the defendant’s offer to prove by parol evidence an asserted alteration or reformation of the contract. Gianni v. Russell & Co., Inc., 281 Pa. .320, 323, 126 A. 791." It was the trial court’s action in that connection which the appellant most strongly urged upon us as error. The remaining assignments are equally without merit.

The judgment of the District Court is affirmed.