My child is 18 and graduating high school. He plans to go to college, does child support continue?

What does your court order say? It should say in there when support is supposed to stop.

p.s. please don't start multiple threads for the same issue.
And also, please pay attention to which board you are posting on. This should have been posted in the family law forum. :)
https://www.askmehelpdesk.com/children/using-forum-read-first-364261.html

Typically the stop age is 18, however in Illinois the court may make provisions for expenses whether the child is minority or majority. Some states have laws holding the non-custodial parent obligated for education expenses, some states don't. Check out the laws for your state or you can check this link, however I don't know how accurate it is.

Child Support - Child Support And College Tuition (http://divorcesupport.about.com/od/childsupportresources/a/childsupportcol.htm)