Duration of Support.

(a)

Except as set forth in subdivision (b), the duration of a support order is determined by the law of the state or foreign country that issued the order which defines the age of majority and/or emancipation.

(b)

For cases with a Convention support order, the duration of support is governed by the law of the country that issued the order which defines the age of majority and/or emancipation, or until the child is 21 years old, whichever occurs first.

(c)

The duration of a support order may be modified only to the degree it could be modified under the law of the state or foreign country that issued the order.