Hmm, those answers seem to contradict slightly, so I'll elaborate.
I've a page at the site called 'hub.php'
it takes a 'target' as a variable, which it uses to include the correct PHP file, containing details like which banner to use, text, image links etc. hub.php then builds the page according to the supplied variables:
hub.php?target=history/history1.php
The supplied page name is crosschecked against a list of allowed targets before executing an include, as a security measure.
If index.html has a link to hub.php?target=history/history1.php will a search engine spider to this address?
and if history1.php has a link to hub.php?target=history/history2.php will this link be followed too?