The general grounds of the motion insist that the evidence did not support the verdict because there was no competent evidence as to the market value of the plaintiff’s piano before and after damage. The plaintiff testified the piano had a reasonable market value of $1,000 prior to damage, and in her opinion she could not get over six or seven hundred dollars for it afterwards. This was competent evidence as to market value, and the general grounds are without merit. National &c. Ins. Co. v. Darby, 48 Ga. App. 394 (3) (172 S. E. 74); Cohn v. Rigsby, 60 Ga. App. 728, 729 (5 S. E. 2d 93); Warren v. State, 76 Ga. App. 243, 245 (45 S. E. 2d 726).

2. Special ground 1 of the motion for new trial presents the contention that the trial judge erred in permitting a certain letter in evidence. The ground does not reveal the contents of the letter, and consequently this court is unable to pass upon its *222 admissibility. Bullock & Co. v. Cordele Sash &c. Co., 114 Ga. 627 (3) (40 S. E. 734); Cordele Sash &c. Co. v. Wilson Lumber Co., 129 Ga. 290 (1) (58 S. E. 860); Sasser v. Pierce, 9 Ga. App. 27 (70 S. E. 197); Perry v. Independent Daughters of Bethel, 11 Ga. App. 498 (75 S. E. 819).

Judgment affirmed.