Phase 2b Epidemic Model Extensions

I added a doctor breed and code blocks to populate it into the world, as well as collision behavior for turtles colliding with doctors.
I was unable to save my project to my Public Gallery. Thought I did the correct steps to get it there, but it does not show up. Will review instructions for this andtry again later, and/or check with fellow students and instructors at training tomorrow.

I decided to allow the doctors to become ill also to increase the rate of infectivity.
http://www.slnova.org/Ywhitehead/projects/367019/
I struggled with the specific code necessary to make this happen.
I need help with knowing under which screen the code goes: world vs turtle