if statement over multiple PHP files

Is it possible to use the IF statement over multiple PHP files?

I have one page sending data to two other pages. The first receiving page needs to receive a   while the other page needs to have the "\040" format for it to work.

My idea was something that uses the if statement to check what page you are in. If you are in the page index.php use   else use "\040"

Am i thinking to complicated?

Also Don't tell me to just write a spacebar. this will not work. It won't outprint anything on the second receiving page anymore. My current solution to this problem is using _ in stead of spacebar. Wich isn't the best solution.