The following finding of fact made by the trial judge is critical to all questions raised on this appeal:

“9. Trustees in 1972 as owner of the account due from defendant, for consideration, sold and assigned said account to the plaintiff herein. The assignment of the account was later acknowledged in writing by the assignor (Trustees) and assignee (plaintiff, Piedmont) and also by the defendant on October 23, 1974.”

By assignments of error numbers 1, 2, 3 and 4 defendant contends that the judge erred in the admission and exclusion of certain evidence. By assignments of error numbers 9, 12 and 16 defendant argues that Finding of Fact No. 9 is not supported by competent evidence. By assignments of error numbers 11 and 12 defendant asserts that plaintiff is not the real party in interest because the assignment was for collection only.

Resolution of all questions raised by these assignments of error depends on whether there is any competent evidence in the *480record to support Finding of Fact No. 9. There is a strong presumption that when the judge is the trier of facts and conflicting evidence is presented, some competent and some incompetent, he bases his findings on the competent evidence and disregards the incompetent evidence. City of Statesville v. Bowles, 278 N.C. 497, 180 S.E. 2d 111 (1971). Thus, if the record reflects any competent evidence to support the findings “they are binding on this Court even though there is evidence to the contrary.” Cogdill v. Highway Commission, 279 N.C. 313, 320, 182 S.E. 2d 373, 377 (1971).

The essential elements of a valid assignment are “an assignor, an assignee, and a thing assigned.” Morton v. Thornton, 259 N.C. 697, 699, 131 S.E. 2d 378, 380 (1963). In the present case the “thing assigned” was the defendant’s indebtedness (the account) of $18,200.00 to the assignor. The trial court found and concluded that the defendant was indebted to Carolina in the amount of $18,200.00 for cattle sold. The defendant concedes in his brief that there is evidence in the record to support this finding. Thus, the first essential element of a valid assignment, “a thing assigned,” was established.

Plaintiff’s Exhibit 6 purports to be an assignment from “Carolina Cattle Company of Betty Zaitz and Kenneth Stults, trustees” to plaintiff of an itemized account between defendant and Carolina, including the $18,200.00 indebtedness here in issue. Thus, in light of the above presumption we think that if plaintiff’s Exhibit 6 is competent evidence then Finding of Fact No. 9 is sufficiently supported to withstand this challenge. Upon proper authentication an instrument such as plaintiff’s Exhibit 6 is admissible. It is an established rule of evidence that such authentication may be accomplished by “any evidence tending to show the execution of the instrument.” Henrico Lumber Co. v. Dare Lumber Co., 185 N.C. 237, 239, 117 S.E. 10, 11 (1923); see also Stansbury, North Carolina Evidence, Brandis Revision, § 195. In the present case plaintiff offered the testimony of an attesting witness to the assignment and that of the agent of the assignor. Both witnesses acknowledged the document and the signing of their names thereon, and both also identified the third signature on the document as that of Kenneth Stults, trustee. This evidence was clearly sufficient to authenticate the document. Accordingly, Exhibit 6 was competent to support Finding of Fact No. 9.

*481Defendant, citing Abrams v. Cureton, 74 N.C. 523 (1876), also argues that the alleged assignment was for collection only, and that therefore, plaintiff is not the real party in interest. Exhibit 6 is again competent evidence to negate this contention and support Finding of Fact No. 9 that the “[tjrustees . . . for consideration, sold and assigned said account to the plaintiff ...” The case cited is readily distinguishable. In Abrams the plaintiff’s testimony as well as the assignment itself clearly disclosed consideration for the notes assigned, and that he agreed to collect on the notes and pay over the money received to the assignor, retaining reasonable compensation for his services. The assignment in this case, Exhibit 6, contains no words indicating an intent that the assignment be for collection only. To the contrary, the assignment demonstrates that the intent was to “sell and assign . . . the accounts owed by Carl Hall, Jr. and any and all rights of suit and collection thereon.” Defendant’s contention is without merit.

Thus, we hold that Exhibit 6 was competent evidence to support Finding of Fact No. 9 and that there was absolute assignment of the $18,200.00 account for consideration. The judgment appealed from is affirmed.

Affirmed.