plaintiff in seeking those permits. The issue for determination then is whether the plaintiff exercised such effort and diligence in attempting to secure these permits sufficient to justify the return of the $25,000 deposit specified in the addendum to the contract. The parties have correctly asserted that one who prevents or makes impossible the performance or happening of a condition precedent, upon which his liability by the terms of a contract is made to depend, cannot avail himself of its nonperformance. Walker v. Chancey, 96 Fla. 82, 117 So. 705 (1928); Hart v. Pierce, 98 Fla. 1087, 125 So. 243 (1929). Such a situation is not presented here. In fact, the plaintiff, Hamilton, was expressly bound to use reasonable efforts and diligence in seeking these permits. Cf. Chancey, supra (<HOLDING>). Here the record clearly reveals extensive and
recognizing an implied fourth amendment action for damages recognizing implied duty to market recognizing implied obligation to use reasonable diligence holding that the plaintiff had an implied duty to use reasonable efforts to elicit particular business and to hand it over to the defendant holding that inquiry notice triggers an investors duty to exercise reasonable diligence and that the  statute of limitations period begins to run once the investor in the exercise of reasonable diligence should have discovered the facts underlying the alleged fraud