Making an entrance page and an index (home) page query?

Question

Hi All,
I've not done anything this way before but for a uni web design and development assignment, I've to firstly design a website with all the theory and how it will all come together.
Therefore, I'm wanting mine to be a little different from the generic kind and whilst I'm basing my subject matter on Tigers and the several species of, I'm creating an entrance page in fireworks that is the following;
I'm planning on sectioning up and placing hotspots around the interior of the tiger body, this will enable viewers to select and go to set pages like "about" "tiger zone" "contact" and so on.
However, I still need a traditional-ish homepage but I'm unsure how to make it that whilst people come in via the entrance page ( as above and the main url) whenever they've left this page to go in to the main homepage, they don't return via any of the main sites navigation menu / links back to this entrance page, is this possible in anyway?
I'm trying to get my own head around this and I have spent a number of hours researching this issue but I cannot find any resource that is anything like what I'm needing to do.
Thanks as always people.
Regards,

Answer 1

Yes, 2nd landing page will be the 'traditional' homepage.
This case, the tiger page will have to be 'index.php' so it'll load when your site is entered in a browser. Why PHP - we'll get to that in a bit.
Let us use, lets say a cookie to see if the user has already been on your index.php (which is your tiger page). If they already have, they will be taken to index2.html (the 2nd homepage - which doesn't have to be php as we aren't using any cookies/ sessions here).
Something like this should work:
<?php
// please note there is a dot prefixed in '.yourdomain.com':
setcookie('homepage', 1, time() + 365*24*60*60, '/', '.yourdomain.com');
if(!empty($_COOKIE['homepage']))
   header('Location: http://yourdomain.com/another_page.html');
   exit;
// you could add more PHP code (if you require), but ensure this patch of code is right at the top of your tiger index page
?>
This should be placed at the very top of your tiger index page which is your initial homepage when users enter your site.
This is how it works:
homepage - the defined name for this cookie
1 - enables the cookie
time() - expiration value for the cookie. The value suffixed with 'time()' is for 1 year - meaning the cookie will remain active for 1 year. If you want it to exist until the browser is closed, set it 0 like this:
setcookie('homepage', 1, 0, '/', '.yourdomain.com');
The / next to time is the areas within your domain that the cookie is available for. / denotes higher most domain path. This is useful if your index.php file (main splash page) is located within the main domain root itself. If not, if it is located somewhere like yourdomain.com/tigerhome, set that to this:
setcookie('homepage', 1, time() + 365*24*60*60, '/tigerhome/', '.yourdomain.com');
Please notice the trailing and prefix slashes for the folder value
yourdomain.com - is the main value of your domain itself. Please note the prefixed dot [.] before the yourdomain.com.
How the header works:
   header('Location: http://yourdomain.com/another_page.html');
If the cookie called 'homepage' exists, then when the user is trying to load index.php, the header condition is read by the browser first. If it is true, the user is taken to another_page.html. If not, the user is allowed to continue viewing index.php page.
The reason we have this at the very top is because when the user attempts to load up index.php page, you dont want the content to be shown before redirect happens. Hence, the header condition along dependant on the cookie is first read by the browser.
If you want custom time setting - maybe 1 day, set it to this:
setcookie('homepage', 1, time() + 1*24*60*60, '/', '.yourdomain.com');
5 hours, this:
setcookie('homepage', 1, time() + 1*5*60*60, '/', '.yourdomain.com');
And so on...
Note: The cookie will expire if the user clears browser cookies manually!
But this is the basic way of getting a cookie set for getting what you want done.
Also, I've set up a test page on my domain for you - expires in 1 year from first visit. Loads on index.php and redirects to test2.html if the cookie is already set. Try it out for yourself here.
Trust this helps.
-ST