LiveCycle -- grey out certain fields when selecting specific sections of the form

Hi all,

I would like to design a form that would, when certain sections of the form are selected (with a check mark), grey out other, irrelevant, sections. In addition, I would like to ensure that the sections that have been selected by the user are mandatory, i.e., there would be a pop-up error message directing them to fill out the sections. Any advice would be greatly appreciated. Thank you!