However, the affidavit of Clarkcraft's president was not sufficient to create a presumption of delivery either under the terms of the contract or under general principles of law as there is no evidence that, within the allowed period of time, the letter dated May 2, 1988, was deposited in the mail, properly addressed and with sufficient postage prepaid. Edmondson v. Air Service Co., 123 Ga. App. 263 (2) ( 180 S.E.2d 589). The evidence negating any satisfaction of the notice requirement for objections concerning the proposed plat was not contradicted. Cambron v. Cogburn, 118 Ga. App. 454, 456 (4) ( 164 S.E.2d 350). 2.

Since there was evidence sufficient to avoid a directed verdict on appellant's counterclaims, and since a verdict in her favor for an amount exceeding that claimed in rent at the time appellee sought the dispossessory warrant would negate appellee's claim for possession, the trial court erred in directing a verdict against appellant for possession of the premises. 3. While it appears that the trial court may have erred in excluding from evidence sua sponte a certified copy of the Atlanta Housing Code (see Cambron v. Cogburn, 118 Ga. App. 454 (1) ( 164 S.E.2d 350) (1968)), we also note that appellant "raised no such specific objection in the trial court. `An enumeration of error complaining of admission of evidence . . . presents nothing for decision by this court where no objection was made at the trial.' [Cits.

6. Plaintiff enumerates as error the admission of, and the charge upon, certified copies of certain city ordinances when the certification did not recite they were still of full force and effect. This is not required. Cambron v. Cogburn. 118 Ga. App. 454 ( 164 S.E.2d 350). 7. Plaintiff contends the charge on emergency was error because the defendant caused the emergency and may not use it to excuse his conduct.

5. Defendant tendered and the court admitted into evidence a copy of § 30.199 of the Traffic Code of the City of Atlanta, together with the adopting ordinance, duly certified — showing, according to the minutes of the mayor and aldermen, the code to have been adopted August 5, 1957. It was objected to on the ground that the certificate did not show the ordinance and code section to have been a valid one on the date of the occurrence here in question, January 6, 1964. The objection was overruled, and we think properly so. Cambron v. Cogburn, 118 Ga. App. 454 (1) ( 164 S.E.2d 350); Nashville, C. St. L. R. v. Peavler, 134 Ga. 618 (2) ( 68 S.E. 432). "It will be presumed that a municipal ordinance is valid, and the burden of establishing its invalidity is on the person asserting it." Hamilton v. North Ga. Elec. c. Corp., 201 Ga. 689, 690 ( 40 S.E.2d 750).

Because the medical statements were sufficiently identified and supported by oral testimony, we are unable to conclude that their admission was error.See Cambron v. Cogburn, 118 Ga. App. 454, 164 S.E.2d 350 (1968); Johnson v. Rooks, 116 Ga. App. 394, 157 S.E.2d 527 (1967). III. Instructions