APPLICATION. Applying is simple! Fill out the form below to get started.Applying to Central Illinois CEO has never been easier. Complete the Request More Information form to be notified when the application opens. Who must file Form IL-1120-ST? You must file Form IL-1120-ST if you are a small business corporation ("S corporation"), as defined in Internal Revenue Code. The following are steps for completing an application for IDHS funding. Review the requirements for your grant. The following is meant to provide guidance to the basic steps you must complete to become a CILA provider. Forms on this website are PDFs with fillable fields.