what do you mean?

what i want is this.... if i go to resourc.cfm and dont have any variables attached, i want my cfinclude to include "main.cfm" but if i go to resource.cfm?p=sub, i want it to include sub.cfm.

i have it setup to include the argument that i sent through as a parameter but i just dont know how to do it so if their is no argument sent, that it will include a default page