How exactly would the variables in these files change?
I guess what im asking is, why do you need to include them from 4 diff files if they're always gonna be the same?
What I would do if they are always gonna be the same, but used in different files:
1 File - config.php - put ya 4 variables here.
4 Files - include("config.php");
Other Files requiring these Vars - include("config.php");