Switching to https for just one page then back to http

Have a code snippet that will send to https but entire site is https after

[scalp8]

Here's the snippet I'm currently using:

//force redirect to secure page
if($_SERVER['SERVER_PORT'] != '443') { HEADER
('Location: ['.$_SERVER['HTTP_HOST'].$_SERVER...]
['REQUEST_URI']); exit(); }

This works great to refer the requested page to https instead of http, but the entire session from then on is in https. Is there a way to add to this so that it refers back to http once the page is left? I've seen some solutions using the htaccess file, but if possible it just seems easier to me to do it on just the selected pages that I need to be secure. Thank you.

[phranque]

the links on the secure page should be fully qualified including the protocol specification (http:).

[edited by: eelixduppy at 4:54 am (utc) on Jan. 7, 2009]
[edit reason] disabled smileys [/edit]

[scalp8]

phranque,
Thank you for your prompt reply. As a site owner who realized that I could benefit more if I learned some development skills, I am new to this so forgive my lack of what may seem like common knowledge. Could you clarify for me which links need to be fully qualified? There's the obvious one "'Location: [.......",...] but that seems to direct to the secure page. Where would I put the one to direct back to http?

[phranque]

all of your navigation links should be absolute urls instead of relative urls.

[scalp8]

My site has a lot of pages. Perhaps the htaccess would be a simpler route. Are there any benefits to using absolute urls or using the htaccess file to control this?