You may be eligible to file for an adjustment of status application for him, depending on how he entered, his intentions at the time, and other immigration issues. Depending on jurisdiction, a person can sometimes file even if out of status and does not need to depart the United States. I encourage you to make an appointment now with a competent immigration attorney in your jurisdiction who can analyze your case fully.
Answered on Jul 19th, 2011 at 1:28 PM