EbviN, J.

Tbe plaintiff makes these assertions by bis assignments of error :

1. That tbe court erred in dismissing tbe ■ action upon a compulsory nonsuit.

2. That tbe court erred in rulings respecting evidential matters.

We will consider tbe assignments of error in tbe order stated above.

When a person deposits bis money in a bank without any agreement to tbe contrary; tbe ownership of tbe .money passes from him to tbe bank, *331 and the bank becomes his debtor for the amount of the money deposited. Bank v. Weaver, 213 N.C. 767, 197 S.E. 551; Williams v. Hood, 204 N.C. 140, 167 S.E. 574; Bank v. Bank, 197 N.C. 526, 150 S.E. 34; Woody v. Bank, 194 N.C. 549, 140 S.E. 150, 58 A.L.R. 725; Wall v. Howard, 194 N.C. 310, 139 S.E. 449; Trust Co. v. Spencer, 193 N.C. 745, 138 S.E. 124; Corporation Commission v. Trust Co., 193 N.C. 696, 138 S.E. 22; Trust Co. v. Rose, 192 N.C. 673, 135 S.E. 795; Graham v. Warehouse, 189 N.C. 533, 127 S.E. 540; Reid v. Bank, 159 N.C. 99, 74 S.E. 746; Hawes v. Blackwell, 107 N.C. 196, 12 S.E. 245; Boyden v. The President and Directors of the Bank of Cape Fear, 65 N.C. 13. The debt thus created is subject to the rule that ordinary business contracts for money due or to become due are assignable. Wike v. Guaranty Co., 229 N.C. 370, 49 S.E. 2d 740; Bank v. Jackson, 214 N.C. 582, 200 S.E. 444; Fertilizer Works v. Newbern, 210 N.C. 9, 185 S.E. 471; Trust Co. v. Williams, 201 N.C. 464, 160 S.E. 484; Bank v. School Committee, 121 N.C. 107, 28 S.E. 134; Motz v. Stowe, 83 N.C. 434; 9 C.J.S., Banks and Banking, section 288. A valid assignment may be made by any contract between the assignor and the assignee which manifests an intention to make the assignee the present owner of the debt. Hall v. Jones, 151 N.C. 419, 66 S.E. 350; Motz v. Stowe, supra; Winberry v. Koonce, 83 N.C. 352; Ponton v. Griffin Bros. & Co., 72 N.C. 362; Thigpen v. Horne, 36 N.C. 20; 6 C.J.S., Assignments, section 41. The assignment operates as a binding transfer of the title to the debt as between the assignor and the assignee regardless of whether notice of the transfer is given to the debtor. Trust Co. v. Construction Co., 191 N.C. 664, 132 S.E. 804; Chemical Co. v. McNair, 139 N.C. 326, 51 S.E. 949. Notice to the debtor is necessary, however, to charge him with the duty of making payment to the assignee. Chemical Co. v. McNair, supra; Bank v. School Committee, 118 N.C. 383, 24 S.E. 792. This duty arises whenever the debtor receives notice of the assignment, irrespective of who gives it. Ellis v. Amason, 17 N.C. 273; 6 C.J.S., Assignments, section 74. The code of civil procedure requires every action to be prosecuted in the name of the real party in interest. G-.S. 1-57. As a consequence of this requirement, a depositor cannot maintain an action against a bank to recover a deposit when it appears from his own evidence that he has assigned the deposit to a third person and has no further interest in it. Vaughan v. Davenport, 157 N.C. 156, 72 S.E. 842.

When these rules of law are applied to the case at bar, it becomes obvious that the compulsory nonsuit was proper. This is true because the plaintiff’s own evidence showed that he assigned his right to the entire deposit in controversy to the Lipe Motor Lines, Incorporated, on 5 January, 1949, and that in consequence he has no further interest in it.

*332 The assignments of error based on rulings in respect to evidential matters are discussed in the numbered paragraphs which follow.

1. The plaintiff noted certain exceptions to rulings of the court which permitted counsel for defendant to elicit from plaintiff on cross-examination oral evidence of the contents of his written contract with the Lipe Motor Lines, Incorporated. The assignment of error founded on these exceptions is unavailing to plaintiff on his appeal. He lost the benefit of the exceptions covering the receipt of this particular evidence by testifying without objection to substantially the same facts in other portions of his examination. Sprinkle v. Reidsville, 235 N.C. 140, 69 S.E. 2d 179; Spivey v. Newman, 232 N.C. 281, 59 S.E. 2d 844.

2. The plaintiff was asked these questions by his own counsel on his re-direct examination: (1) “Would you state to his Honor and the jury what other agreements, if any, you may have had with Lipe Motor Lines, Inc., concerning the status of this account?” (2) “Do you know whether or not the Lipe Motor Lines, Inc., had opened a separate account from yours?” The defendant objected to these questions, and the court sustained its objections. The plaintiff noted exceptions to these rulings without showing what answers he would have made to the questions had he been allowed to respond to them. The assignment of error based on these exceptions falls under the ban of the rule that the question of whether error was committed in excluding evidence will not be considered on appeal unless the appellant shows what the rejected evidence would have been. Francis v. Francis, 223 N.C. 401, 26 S.E. 2d 907; In re Wilder's Will, 205 N.C. 431, 171 S.E. 611.

3. The plaintiff took an exception to the ruling of the court excluding his opinion that the terms of his written contract with Lipe Motor Lines, Incorporated, had never been “fulfilled.” Since his complaint ignores this contract and bases his right to recover on its nonexistence, the plaintiff’s insistence that the exclusion of his opinion respecting the supposed nonfulfillment of the terms of the contract was prejudicial to his rights in the action leaves us in somewhat of a quandary. The plaintiff would have no just cause for complaint on this score, however, even if the pleadings made the matter involved in the opinion germane to the issues joined between the parties. The opinion would be rendered incompetent in that event by the rule that “under ordinary circumstances a witness in testifying is to be restricted to facts within his personal knowledge, and his opinion or conclusion with respect to matters in issue or relevant to the issue may not be received in evidence.” 32 O. J.S., Evidence, section 438. See, also, in this connection: Wolf v. Arthur, 112 N.C. 691, 16 S.E. 843, and Bailey v. Poole, 35 N.C. 404.

For the reasons given, the judgment dismissing the action on a compulsory nonsuit is

Affirmed.