Section 4908 provides: "(a) a tribunal of this state may exercise jurisdiction to establish a support order if the petition or comparable pleading is filed after a pleading is filed in another state only if all of the following circumstances exist: "(1) the petition or comparable pleading in this state is filed before the expiration of the time allowed in the other state for filing a responsive pleading challenging the exercise of jurisdiction by the other state. "(2) the contesting party timely challenges the exercise of jurisdiction in the other state. "(3) If relevant, this state is the home state of the child. "(b) a tribunal of this state may not exercise jurisdiction to establish a support order if the petition or comparable pleading is filed before a petition or comparable pleading is filed in another state if all of the following circumstances exist: "(1) the petition or comparable pleading in the other state is filed before the expiration of the time allowed in this state for filing a responsive pleading challenging the exercise of jurisdiction by this state. "(2) the contesting party timely challenges the exercise of jurisdiction in this state. "(3) If relevant, the other state is the home state of the child." Section 4908 is a part of the Uniform Interstate Family Support Act (UIFSA). That statute was enacted in this state in 1997, and is based on a uniform law proposed by the National Conference of Commissioners on Uniform State Laws in 1996. (See 9 pt. IB West's U. Laws Ann. (1999) U. Interstate Family Support Act, p. 235.) UIFSA replaced the Uniform Reciprocal Enforcement of Support Act, and now governs child and spousal support orders in interstate cases. (Id., Prefatory Note, p. 238; see former 4800 et seq.) Section 4908 is taken from section 204 of UIFSA. (The language is almost identical. However, the California version adds the phrase "all of the following circumstances exist" after "only" in the initial sentence of subdivisions (a) and (b).) ( 4908.) Section 4908 deals with both child support and spousal support orders. the commissioners' comment about the child support aspect is instructive. The comment points out that the federal Parental Kidnapping Prevention Act (PKPA; 28 U.S.C. 1738A) chooses the home state of the child to establish priority between tribunals in different states, and "given the preemptive nature of the PKPA, and the possibility that custody and support are both involved in the case, UIFSA opts for the federal method of resolving disputes between competing jurisdictional assertions by establishing a priority for the tribunal in the child's home state. If the child has no home state, 'first filing' controls." (9 pt. 1B West's U. Laws Ann., supra, UIFSA, com. to 204, p. 283.) The "home state" is, generally, the state in which a child lived with a parent or person acting as a parent for at least six months immediately preceding the time the petition is filed. ( 4901, subd. (d); 9 West's U. Laws Ann., supra, UIFSA, 101, subd. (4), p. 256.) These provisions would make little sense if their application depended upon a challenge to the jurisdiction of the state in which dissolution proceedings are first commenced, even though no child support is sought in those proceedings. It would make even less sense to read the challenge to jurisdiction provision to apply to spousal support and not to child support when the language offers no such distinction. (See State of South Dakota v. Brown (1978) 20 Cal. 3d 765, 771 144 Cal. Rptr. 758, 576 P.2d 473 uniform acts are construed to carry out object of uniformity; Smith v. Superior Court (1977) 68 Cal. App. 3d 457, 463 137 Cal. Rptr. 348 commissioners' notes entitled to substantial weight in construing uniform law; Merrill v. Department of Motor Vehicles (1969) 71 Cal. 2d 907, 918 80 Cal. Rptr. 89, 458 P.2d 33 statute construed with reference to entire statutory system of which it is a part; In re Morgan (1966) 244 Cal. App. 2d 903, 910 53 Cal. Rptr. 642 in ascertaining legislative intent, court examines general tenor and scope of entire enactment, rather than exact phraseology in which intent is expressed.)