How to run one php app from another?

Hi gang: This seems like so obvious a question, I am reluctant to ask. In any event, I simply want my php application to run another, like so: switch (option) { case a: run a.php; exit; break; case b: run b.php; exit; break; case c: run c.php; exit; break; } I know that from within an application I can run another php application via a user click (.e., button), or from javascript event (onclick), or even from cron. But, what if you want to run another application from the results of a calculation inside your main application without a "user trigger". How do you do that? I have tried header("Location: http://www.example.com/"); ob_start(), ob_flush() and such, but I can't get anything to work. Is there a way? Thanks. tedd -- ------------------------------------------------------------------------------------ http://sperling.com http://ancientstones.com http://earthstones.com