Set SSL on joomla site to work only on Vieturmark Checkout

This is a very small project to configure fro SSL certificate to be activatage only whne a customer is checking out. The certificate is already installed on the site but at this point when you navigate back from the checkout option the entire site goes back to HTTPS instead of HTTP. So the requirement here to to ensure that HTTPS is tied only to the check module in Vituremart and not the entire site. Also when a customers is checkling out and wants to continue shopping the site, it show go back to HTTP. So HTTPS should only be activated when the customer is checking out. take a look at our site here: www.mmedicalsupply.com.