title: Allow page view only if coming from one other external URL
body: <p>Good morning!
  Please help :-)</p>
  
  <p>What:
  I want to allow a page to be viewed only if the user is coming from one other external domain page. In other words, you can't see URL "B" unless you came from URL "A."  I don't want them to be able to access the page coming from any other URL or pasting the link in the browser. Both URL A and B are static links.  How can I do that? </p>
  
  <p>Why:
  I have a static Weebly "member only" page with a static link to a Drupal site page. If they are a member on my Weebly site, they can see the link and use it. But if someone uses that URL to view the page coming from any other page or just pasting the URL in the browser, I want the page to not display or be redirected back to another static link in my Weebly site. I do not want to have them register as a member on two different sites. I'm keeping the Drupal site for the Views capability to build the page they will view.</p>
  
  <p>Note: I have read that HTTP_REFERER is not a very secure solution. Is that the only option? </p>
  
  <p>Hope this makes sense! Thank you for your expertise and help.</p>