What happens if the support paying, non custodial parent resides in another state?

You've gone through a Bucks County divorce and you have custody of the children.  Then, your ex-spouse moves to another state.  What happens?  

In such situations the child support order will be handled by the appropriate agency in the state of the non custodial parent.  The Bucks County Domestic Relations office will be the liaison between the two states and the Pennsylvania custodial parent.