
262 S.E.2d 376 (1980)
Dr. Terry O. BOWMAN
v.
William A. HILL; Jay W. Terrell and wife, Shirley H. Terrell.
No. 7922SC357.
Court of Appeals of North Carolina.
February 5, 1980.
*377 Brinkley, Walser, McGirt, Miller & Smith by Gaither S. Walser, Lexington, for plaintiff-appellee.
Grubb, Penry & Penry by Robert L. Grubb, Lexington, for defendants-appellants.
HILL, Judge.
Defendant assigns as error the lower court's judgment that defendants were obligated to plaintiff under the terms of the written agreement. We find that the court was in error.
Where the language of a contract is plain and unambiguous the construction of the agreement is a matter of law for the court, and a patent defect [emphasis added] or omission cannot be cured by matters outside the instrument.
. . . [T]he court may not, under the guise of construction, ignore or delete any of its provisions, nor insert words into it, but must construe the instrument as written . . .. 3 Strong's N.C. Index 3d, Contracts § 12.1, pp. 391-2.
One of the elements of a valid contract is a promise, which has been defined as an assurance that a thing will or will not be done. "The mere expression of an intention or desire is not a promise, however. . .." 17 Am.Jur.2d, Contracts § 2, p. 334.
An apparent promise which, according to its terms, makes performance optional with the promisor no matter what may happen, or no matter what course of conduct in other respects he may pursue, is in fact no promise. Such an expression is often called an illusory promise. Williston, Contracts § 1A (3d ed. 1957).
When we give the ordinary and usual meaning to the words of the contract desire and desirousit is apparent that they express a wish or request. Certainly, they do not carry the thrust of a promise to do or refrain from doing anything with regard to the remaining property. There is no expressed obligation to develop the property at anytime.
In the case of Jones v. Realty Co., 226 N.C. 303, 37 S.E.2d 906 (1946), the plaintiff sued to recover a sales commission for procuring a purchaser who was ready, willing, and able to buy land on terms set out in an agreement. The trial court interpreted the agreement between the parties to mean that the commission was to be paid "when" and only when"the deal is closed up." The deal never closed, and the Court said at p. 306 that,
It can make no difference whether the event be called a contingency or the time of performance. Certainly, under either construction, the result would be the *378 same; since, if the event does not befall, or a time coincident with the happening of the event does not arrive, in neither case may performance be exacted. Nor will it do to say that a promise to pay `when the deal is closed up' is a promise to pay when it ought to be closed up according to the terms of the contract. Such is not the meaning of the words used. It is the event itself, and not the date of its expected or contemplated happening, that makes the promise to pay performable. Amies v. Wesnofske, 255 N.Y. 156, 174 N.E. 436, 73 A.L.R. 918.
By the conveyance of the property on 4 February 1977, the defendants served notice to the plaintiff, and to all the world, that they would never develop the property, and such conveyance and notice terminated the agreement, if any there was.
For the reasons stated above, the decision of the court below is
Reversed.
MORRIS, C. J., and PARKER, J., concur.
