NAPERVILLE, Ill. (AP) -- Former 1960s radical William Ayers is scheduled to speak at a suburban Chicago high school next month. On the campaign trail President Barack Obama was scrutinized for his ties to Ayers. The University of Illinois at Chicago professor was a founder of the radical Weather Underground and once served on a school reform board with Obama. Naperville North High School officials say Ayers will be limited to speaking about three subjects. Those are Ayers' time with the Weather Underground, the attention he received on the campaign trail and education. The school's assistant principal says students must have a signed permission from their parents to attend. Ayers will speak at the high school on April 8.