Hide Header & Footer

Site URL: http://www.nkybestfestival.com

I am working on a site created by someone else. The site was developed on the Five template and we have a Business Plan. I'm trying to hide the header & footer for a couple of new landing pages by using the Page Header Code Injection for the new pages, which seems like it's pretty straightforward; however, I've tried a number of variations of code and nothing seems to work. I'm trying to avoid getting into the Custom CSS, etc. as I'm not a pro and don't want to start messing around with coding and potentially screw something up. Any help would be appreciated. 

<style>
#page-header {
  display: none;
}
#page-footer-wrapper {
  display: none;
}
</style>