Checkbox HTML issues

HI All,

I am using a 24-item checklist of health problems that people can choose from to describe their health problems. This was done in html with data validation at the beginning to ensure that "none" could not be selected with additional conditions. Basically, I want a health conditions survey to follow only if they selected one of the conditions. That isn't an issues. It is when I have participants that select "none of these" that I want it so that participants can skip the rest of the questionnaire.

I have attached the html file, and the questionnaire file in order to more easily understand the problem.

Thank you in advance!!