"`Fraudulent intent usually must be proved by circumstantial evidence and such circumstances may, by their number and joint consideration, be sufficient to constitute proof.'" Id. (quoting Nally v. Olsson, 134 So.2d 265, 267 (Fla. 2d DCA 1961); Tornwall v. Carter, 106 So.2d 96, 99 (Fla. 2d DCA 1958)). "`A litigant has a right to trial where there is the slightest doubt as to the facts' in a fraud case." Id. (quoting Dean v. Gold Coast Theatres, Inc., 156 So.2d 546, 549 (Fla. 2d DCA 1963)).