Download and complete Divorce, Child Support, and Maintenance forms from the Illinois Office of the Courts. Complete the on-line application for free child support services if you live in Illinois and the dependent child(ren) lives with you.This alimony calculator is intended only to give a general idea of your spousal maintenance calculations. Learn about the types of alimony available in Illinois, how it's calculated, and the factors courts consider when awarding spousal maintenance. Learn about the types of alimony available in Illinois, how it's calculated, and the factors courts consider when awarding spousal maintenance. How Is Child Support Calculated in Illinois? Child support and spousal support, also referred to as alimony, are two different payments. Child support guidelines are separate from spousal support. They will not affect a marital support order. Child support and spousal support, also referred to as alimony, are two different payments.