My Ex Husband filed a motion to terminated the child support?

He can't terminate his child support. Even if he doesn't have any income at all. My ex isn't working has no income and still has a child support order of 300 a month. Its becoming all back pay and i may never see it but hey, he wants to spend his life in jail so be it. But he'll always have child support even its 20 dollars a month. Reguardless whether you have public assistance or not that doesn't matter.