Appellant takes this appeal from an adverse final judgment entered after a non-jury trial. The judgment awarded damages in the amount of $18,565.07, and pre-judgment interest, to appellee Mary L. Stern for commissions earned on sales of advertisements for “The Winner’s Circle” magazine operated by appellant.

We have carefully considered all of the points raised on appeal in light of the applicable principle that a judgment of the trial court reaches us clothed with a presumption *855of correctness. Furthermore, it is within the trial judge’s province, when acting as trier of both fact and law, to determine the weight of the evidence, evaluate conflicting evidence, and determine the credibility of the witnesses, and such determinations may not be disturbed on appeal unless shown to be unsupported by competent and substantial evidence, or to constitute an abuse of discretion. Bali, Inc. v. Sherwood’s Commercial Brokers of Daytona Beach, Inc., 326 So.2d 21 (Fla. 1st DCA 1975); Jeffreys v. Simpson, 222 So.2d 224 (Fla. 1st DCA 1969); Federated Department Stores, Inc. v. Planes, 305 So.2d 248 (Fla.3d DCA 1974).

The record reveals that while there was conflicting testimony, there was competent and substantial evidence to support the final judgment entered by the trial court. This court will not substitute its opinion for that of the trial court. Accordingly, the judgment appealed is affirmed.

Affirmed.