raising the child support without concent

[424Smudge]

Dad has a child in North Carolina. The original child support order is in North Carolina. Dad moved to Illinois a little over a year ago. He submitted his order of assignment to all of his employers in Illinois that he has had and has had his child support removed directly from his check. He went to court today because the state of Illinois was taking him to court for being in arrears. (He is in arrears but he still pays every month, this is from about 5 years ago when he was unemployed for a year) About 2 years ago mom and dad mutually agreed to lower the child support below the guidelines and filed the ammended order at the courthouse. The Attorney for Illinois is now saying that mom has no say so with that and that he is going to petition the courts here in Illinois to raise the child support ammount. Mom does not collect any assistance from the government so I do not see why the state is interfering with it. How can mom and dad prevent the raise in child support?