#include <panels.h>
put that at the top of your main file
put panels.c in the same dir.
Unless ofcourse you don't make the file's name "panels.c" -
then it'll obviously be <panels.c> just a reminder there!

And yes - as he sais above, put the scripts in the same dir. And type:
#include <panels.c>
In your main script.
Hope this helps!
//Regards, Alof.