A preface. I know nothing about formal programming (aside from some html,some css, and a tiny bit of java script)

I am developing several websites that will all share the same data base. There will be an overlap of products - for example, let's say "shoes." Sveral sites will each sell some of the same products.

There are shopping carts that will allow a site to place a "buy anywhere button" before the database driven shopping cartcheckout pages. That is, a button activates the "add to shopping cart" step of the checkout procedure from the site (and not from the site's data base.)

From this web page one moves on to the actual shopping cart and if the customer wants to continue shopping they can only go back to the last page visited, and not the previous previous thumbs page or even to the site lobby.

I am wondering how to effect a "smart checkout page" that will know from which particular site a customer has come.

What I would like to happen is to have the basic selling template for a product (which is tied to a product's inventory ID# (and is having its inventory modified in the {PHP / MSQL} data base ) insert the appropriate HTML created URL links information for that site onto the data base generated page.

As it is once, a customer has entered the data base there is no way to get back to a particular site.

I can't use "duplicate" pages of the product for each site because that would require different product IDs and the inventory for that product wouldn't be adjusted by a sale.

Maybe it can? Still, I would prefer to have a single selling page per product in the data base, but with different URLS being attached to the HTML designed navigation elements on the page.

I am looking for guidance, since I am not sure if this should be done by Perl, by an Applet, by JavaSCript, C, C+ or some other language or procedure.

Thanks,

Dorian