Arguing that the money Thomas Marsh received when he sold his shares in Wisted’s Supermarket qualified as “income” under Section 505(a)(3) of the Illinois Marriage and Dissolution of Marriage Act, his ex-wife, Susanne Marsh, said he owed 20 percent of the proceeds as child support under a marital settlement agreement. The settlement agreement required Thomas to pay child support of $731 a month (reduced to $231 a month after an offset for maintenance payments) plus “20 percent of all additional …