Checkboxes help!

I am setting up a set of terms and conditions for a client and I want them to be able to either type in YES or tick a checkbox for each service BUT I also want only certain text (paragraphs) to display when the box is ticked. 

e.g. if they tick (write YES) next to the Payroll option then the Payroll section of the terms and conditions would display. If they don't check the box (or write NO) then they Payroll section would be omitted. 

Does anyone know how I do this or even if it is possible?