The plaintiff (husband) has made 35 assignments of error in the record on appeal, and purports to argue 31 of them in his brief. It is impossible to address these separately because they overlap in theory and subject matter. We have determined that this appeal presents two basic questions for resolution.
I. Did the District Court err in affording full faith and credit to the Texas Decree and in ordering its enforcement?
II. Did the District Court err in denying plaintiff’s prayer to modify or supersede the Texas custody award based on changed circumstances, and in failing to make findings of fact to support such denial?
 It is well-established that our courts will accord full faith and credit to the custody decree of a sister state which had jurisdiction over the parties and the cause so long as the circumstances of its rendition remain unchanged. Spence v. Durham, 283 N.C. 671, 198 S.E. 2d 537 (1973), cert. den. 415 U.S. 918 (1974). Husband asserts that the Texas court had lost its jurisdiction over the minor children at the time of the entry of its decree due to their absence from Texas.
The validity and effect of a foreign judgment must be determined by the laws of the state wherein the judgment was rendered. Marketing Systems v. Realty Co., 277 N.C. 230, 176 S.E. 2d 775 (1970). Under Texas law, the Texas Domestic Relations Court did not lose jurisdiction over the parties and the children by virtue of the removal of the children from the State of Texas subsequent to the filing of action which led to the custody decree. Smith v. Ansley, 257 S.W. 2d 156 (Tex. Civ. App. *5861953). Husband admits that the Texas court acquired jurisdiction over him and the children at some stage of the proceedings which were commenced by wife on 25 July 1974. He argues however that the Texas court lost its jurisdiction when he moved with the children to North Carolina in October or November 1975, and thus did not have jurisdiction when the custody decree was entered on December 23, 1975. This argument is without merit.
Husband also asserts that the Texas decree is void on its face, for lack of findings of fact, and thus not entitled to full faith and credit. Again, we look to Texas law. Vernon’s Texas Family Code Annotated § 11.16 provides that “[t]he decree in a suit affecting the parent-child relationship shall recite . . . relevant facts on which the findings and orders are based.” The Texas court in the instant case found merely that the best interests of the children would be served by awarding custody to their mother, the appellee. There were no other factual findings to support the finding.
In Adams v. Adams, 519 S.W. 2d 502 (Tex. Civ. App. 1975), the trial court, as in the instant case, had merely recited the best interests language in making the custody award. On appeal, in the face of an argument that the judgment was void on its face for failure to state facts upon which the custody award was based, it was held, in interpreting the above cited statute, that although the best practice is to recite certain basic facts, where the evidence supports .the findings, the failure to find facts is harmless error. Under Texas law, where there is a specific finding that it is in the best interests of children for their custody to be in a party, the judgment awarding custody establishes a finding that that party was at the time a suitable person to have custody. Thomason v. Thomason, 332 S.W. 2d 148 (Tex. Civ. App. 1959). Thus the Texas decree awarding custody of the children to appellee is not void on its face, and is res judicata as to the issues determined.
Finally, husband contends that the Texas decree is not entitled to full faith and credit because it is not a final judgment. He argues that the language in the decree requiring him to deliver the children to wife on demand renders the decree interlocutory. This argument is feckless. The custody award clearly contains no language which would render it interlocutory. The on demand language merely refers to the execution of the custody decree.
In determining questions of child custody, wide discretion is vested in the trial judge who has the opportunity to see and hear the witnesses; absent abuse of this discretion, the judge’s decision will not be upset. In re Custody of Mason, 13 N.C. App. 334, 185 S.E. 2d 433 (1971). G.S. 5043.7(b) authorizes a court of this state, upon gaining jurisdiction and upon a showing of changed circumstances, to modify or supersede the custody order entered by a court of another state. The party moving for modification assumes the burden of proving a substantial change of circumstances affecting the welfare of the child. Blackley v. Blackley, 285 N.C. 358, 204 S.E. 2d 678 (1974). It must be shown that the circumstances have so changed that the welfare of the child will be adversely affected unléss the custody provision is modified; more must be shown than the removal by one parent of a child from a jurisdiction which might enter a decision adverse to the removing parent. Rothman v. Rothman, 6 N.C. App. 401, 170 S.E. 2d 140 (1969).
 In this case, the district court concluded as a matter of law that there had been “no material changes of circumstances with respect to the custody and welfare of the minor children since December 23, 1975 ...” Although the district court made no underlying findings of fact specifically relating to circumstances, which may or may not have changed, affecting the welfare of the children or the fitness of the parents, it has been held that the trial court is not required to make negative findings of fact justifying a holding that a party has not met his or her burden of proof on an issue. In re Custody of Mason, supra. Assuming that the above conclusion of law is based upon an implicit finding of fact to the same effect, a finding by the district court that there has been no sufficient change of circumstances to justify modification of a custody order is conclusive and binding on this court if supported by competent evidence. In re Harrell, 11 N.C. App. 351, 181 S.E. 2d 188 (1971).
The evidence before the district court and the findings of fact in this case show that indeed no circumstances had changed regarding the welfare of the children since the entry of the Texas decree on December 23, 1975. On that date, the children were living with husband in North Carolina and continued to do so through the proceedings in district court below. As discussed in *588Part I, under Texas law, the judgment awarding custody to wife established that she was a suitable person to have custody. Husband presented no evidence to show any change in that circumstance.
 Husband argues that the district court’s judgment erroneously awarded custody without supporting findings or conclusions. The district court purported to exercise jurisdiction to determine custody in its discretion under G.S 50-13.5(c)(5). A trial court, proceeding under this section either in exercising or refusing to exercise jurisdiction, must make findings of fact regarding the best interests of the child. Mathews v. Mathews, 24 N.C. App. 551, 211 S.E. 2d 513 (1975). However, G.S. 50-13.5(c)(5) should be read to apply only when a custody proceeding is pending in another state. G.S. 5043.7(b) applies when a custody order has been entered in another state. This section allows modification of the foreign decree upon a showing of changed circumstances. Although purporting to act under G.S. 5043.5(c)(5), the district court found that husband had not shown changed circumstances which would warrant modification under G.S. 5043.7(b). As noted earlier, the court is not required to make negative findings of fact. The Texas court ruled on the best interests of the children, and husband failed to show any change in circumstances. To the extent that Mathews v. Mathews, supra indicates that upon according full faith and credit to a foreign custody decree and ordering its enforcement the trial court must make findings of fact as to the best interests of the child, that case is distinguishable from the instant case in that it dealt with an application of G.S. 5043.5(c)(5) when a custody action was pending in South Carolina, and the North Carolina court was ordering the return of the child to the jurisdiction of the South Carolina court for determination of custody.
The judgment of the District Court, Wake County is
Judges Parker and Arnold concur.