I am wondering if it is possible to include server side includes with b2e (I have a side menu and header already on my site) or include my b2e installation as an include in my already existing page?
I think you might be able to get the first way to work. B2evo does so much with urls that I wouldn't even try your second method. To include your menu, just go to /skins/whatever-skin-you're-using/_main.php and find the section that says 'Sidebar begins here.' Add your includes in and see what happens.
I think you might be able to get the first way to work. B2evo does so much with urls that I wouldn't even try your second method. To include your menu, just go to /skins/whatever-skin-you're-using/_main.php and find the section that says 'Sidebar begins here.' Add your includes in and see what happens.