DiLorenzo was an officer, director and shareholder of 100 shares of stock of Valve & Primer. M. Chris Dickson was the chief executive officer and majority shareholder of Valve & Primer. DiLorenzo was employed by Valve & Primer for approximately 40 years prior to the events that led to this lawsuit.

   According to DiLorenzo, on or about May 12, 1987, he informed Valve & Primer that he wanted incentives in any future employment agreements. DiLorenzo claims that, through Dickson, Valve & Primer offered him a 10-year stock option that would allow DiLorenzo to purchase an additional 300 shares at the fixed price of $250 per share. Dickson and the board of directors allegedly favorably voted on the agreement at a meeting held on June 8, 1987.

DiLorenzo claims he received a copy of the minutes of that meeting. DiLorenzo also claims that in reliance on the minutes of the special board meeting, which were never altered or revoked by the board of directors during the time he remained employed by Valve & Primer, he stayed in his job for over nine additional years. According to DiLorenzo, while he was working for Valve & Primer, in reliance upon the minutes of the special board meeting, when he was approached by other companies with employment opportunities he did not follow up on any of these recruitment offers. 

   Valve & Primer claims the 1987 employment agreement between it and DiLorenzo did not contain a stock purchase agreement. The only purported proof of the agreement is an unsigned copy of board meeting minutes of which DiLorenzo had the only copy. Valve & Primer claimed the purported minutes were inconsistent in subject matter and format from other corporate minutes it produces in the ordinary course of business.

   In January 1996, DiLorenzo entered into a semi-retirement agreement with Valve & Primer. Valve & Primer claims he attempted to tender his remaining 100 shares pursuant to a stock redemption agreement. According to Valve & Primer, DiLorenzo demanded $4,000 per share for the remaining 100 shares. It claims DiLorenzo admitted he came up with the proposed share value himself and that no one of any expertise valued the stock. DiLorenzo responded that he had corporate accountants review financial statements before valuing the company’s shares. Valve & Primer declined to purchase the shares at DiLorenzo’s price. This resulted in a dispute between DiLorenzo and Valve & Primer through Dickson. Shortly thereafter, Valve & Primer fired DiLorenzo. After the termination, DiLorenzo claims he attempted to exercise the purported stock purchase agreement.  

   In addition to DiLorenzo, George Christofidis, another long-time employee, attempted to exercise the stock option. * * * In the alternative, DiLorenzo argued before the trial court that, even if the purported agreement was not found to be valid, it should be enforced along promissory estoppel grounds.

   * * *
Analysis

 DiLorenzo argues on appeal that the trial court misapplied the law in finding there was insufficient consideration to support the stock option agreement. He argues that substantial continued employment is sufficient consideration for agreements entered into in the employment setting. DiLorenzo argues that he has provided consideration for the stock option. It was as an incentive for continued employment. He also argues that, even if there was an initial lack of consideration, performance may ameliorate an initial lack of consideration, if the performance was clearly invited. He claims his continued employment for nine years in reliance on the agreement satisfied the condition of the performance being invited. Here he claims Valve & Primer benefitted both from the pre-1987 employment and the post-1987 work. DiLorenzo argues that he was not promising to do something he was already obligated to do, which he concedes would not be valid consideration. 

    Valve & Primer responds that the trial court correctly granted it summary judgment because DiLorenzo failed to show any consideration to support the alleged stock option. Valve & Primer, without admitting that the board meeting minutes are genuine, argues that they indicate that the alleged stock option was given to ‘‘reward’’ him for his long service to the company. Valve & Primer’s position is that, if the alleged consideration for a promise has been conferred prior to the promise upon which the alleged agreement is based, then no contract is formed. Valve & Primer also argues that the argument that the option was based, at least in part, on his claimed continued employment must fail because it relies on something DiLorenzo was already obligated to do. According to Valve & Primer, because DiLorenzo contends that the stock option vested immediately, only past performance could serve as consideration. As the trial court noted, that is insufficient consideration. * * *

   In reply, DiLorenzo contends that there is sufficient consideration to support the stock option. He argues that whether the 1987 corporate minutes are authentic is not an issue on appeal. Since the trial court took the minutes as true, the appellate court should do likewise. * * *  

   The purported minutes of the June 8, 1987, special meeting contain the following relevant language:

‘‘That in order to retain and reward such dedication George Christofidis be given an option to purchase additional shares not to exceed 300; and that Ralph DiLorenzo be given an option to purchase additional shares not to exceed 300. Said option to be exercised within 10 years from below date at the price of $250.00 per share. Each share was to be restricted wherein the share must first be offered to Valve and Primer Corporation to be paid by Valve and Primer Corporation and held as Treasury Stock. Valve and Primer Corporation would be given 45 days to consummate the purchase. In the event that Valve and Primer Corporation did not choose to purchase, said stock would be offered to the existing shareholders on a pro rate basis also to be purchased within 45 days. And in the event the shareholders did not purchase said shares, the shares could be sold to any interested person or persons. Purchase price of shares would be based upon the book value pursuant to a certified audit of the worth of the Corporation at the time of sale.’’ 

   We begin by addressing whether there was consideration for the stock options. ‘‘A stock option is the right to buy a share or shares of stock at a specified price or within a specified period.’’ [Citation.] In order to evaluate the nature and scope of the stock options issued to DiLorenzo, we must assume, for purposes of this portion of our discussion, that DiLorenzo’s corporate minutes are valid.

   ‘‘A contract, to be valid, must contain offer, acceptance, and consideration; to be enforceable, the agreement must also be sufficiently definite so that its terms are reasonably certain and able to be determined.’’ [Citation.] ‘‘A contract is sufficiently definite and certain to be enforceable if the court is able from its terms and provisions to ascertain what the parties intended, under proper rules of construction and applicable principles of equity.’’ [Citation.] ‘‘A contract may be enforced even though some contract terms may be missing or left to be agreed upon, but if essential terms are so uncertain that there is no basis for deciding whether the agreement has been kept or broken, there is no contract.’’ [Citation.] A bonus promised to induce an employee to continue his employment is supported by adequate consideration if the employee is not already bound by contract to continue. [Citation.] Because we are assuming the validity of the document issuing the stock options, we now turn to whether the underlying option is supported by valid consideration so as to make it a proper contract.  

   ‘‘Consideration is defined as the bargained-for exchange of promises or performances and may consist of a promise, an act or a forbearance.’’ [Citation.]

‘‘The general principles applicable to option contracts have been long established. An option contract has two elements, an offer to do something, or to forbear, which does not become a contract until accepted; and an agreement to leave the offer open for a specified time [citation], or for a reasonable time [citation]. An option contract must be supported by sufficient consideration; and if not, it is merely an offer which may be withdrawn at any time prior to a tender of compliance. [Citation.] If a consideration of ‘one dollar’ or some other consideration is stated but which has, in fact, not been paid, the document is merely an offer which may be withdrawn at any time prior to a tender of compliance. The document will amount only to a continuing offer which may be withdrawn by the offer or at any time before acceptance. [Citation.] The consideration to support an option consists of ‘some right, interest, profit or benefit accruing to one party, or some forbearance, detriment, loss or responsibility given, suffered or undertaken by the other’ [citation]; or otherwise stated, ‘Any act or promise which is of benefit to one party or disadvantage to the other * * *.’’’ [Citation.] 

   ‘‘The preexisting duty rule provides that where a party does what it is already legally obligated to do, there is no consideration because there has been no detriment.’’ [Citation.] 

   Focusing on the lack of a detriment to the employee, the trial court found no valid consideration. Based upon our view of the discussion in [citation], the trial court was correct in concluding that the option contract is merely an offer which may be withdrawn at any time prior to a tender of compliance. DiLorenzo could have exercised the option the moment it was purportedly made, then immediately quit, thereby giving nothing to the employer. Though the exercise of the option would require the transfer of money for the stock, the option itself carries with it no detriment to DiLorenzo. Therefore, there was no consideration for the option.

*** 

   We next address DiLorenzo’s claim that he is entitled to the value of the shares of stock based upon the theory of promissory estoppel. DiLorenzo argues that the trial court misapplied the law in finding that there was insufficient reliance to support a claim for promissory estoppel. He claims that, once the trial court decided there was insufficient consideration to support the option contract, promissory estoppel should have been applied by the court to enforce the agreement as a matter of equity. DiLorenzo argues that he detrimentally relied upon Valve & Primer’s promise in that he worked at Valve & Primer for an additional period in excess of nine years in reliance on the stock option agreement. * * * 

   Valve & Primer responds that the trial court was correct in finding insufficient reliance to support the promissory estoppel claim. Valve & Primer argues that the DiLorenzo could not satisfy the detrimental reliance prong of the promissory estoppel elements. Though DiLorenzo claimed he did not act upon offers of employment he claims were made by other companies during the course of his employment with Valve & Primer, he presented to the trial court nothing but his own testimony in support of his claim. Valve & Primer argues that, since DiLorenzo essentially is claiming his stock option vested immediately, he cannot contend that he detrimentally relied upon the purported agreement in the corporate minutes by turning down those other opportunities. * * * For purposes of promissory estoppel, if DiLorenzo’s allegations are taken as true, and the purported option vested immediately, it required nothing of him in order to be exercised other than the payment of $250 per share.

   ‘‘Promissory estoppel arises when (1) an unambiguous promise was made, (2) the defendant relied on the promise, (3) the defendant’s reliance on the promise was reasonable, and (4) the defendant suffered a detriment.’’ [Citation.] Whether detrimental reliance has occurred is determined according to the specific facts of each case. [Citation.]  

   While we would accept that, under certain circumstances, it may be possible for a relinquishment of a job offer to constitute consideration sufficient to support a contract, this is not such a case. There is nothing in the language of the corporate minutes or any other source to be found in this record to suggest that Valve & Primer conditioned the alleged stock option on DiLorenzo’s promise to remain in his employment. While the corporate minutes say the alleged grant of the stock option was intended to ‘‘retain and reward,’’ it contains no mechanism making the retention mandatory. Since the corporate minutes lack a mandatory obligation on which DiLorenzo could have reasonably detrimentally relied, and he could have elected to buy the shares of stock immediately, DiLorenzo’s decision to remain on the job for the additional period of over nine years must be viewed as a voluntary act. Under those circumstances, promissory estoppel would not apply. It was, therefore, not an abuse of discretion to grant Valve & Primer’s motion for summary judgment on that issue.

*** 

    Affirmed.