Stupid Question, how do you referance a UDF on multiple pages

So I’ve created a User Defined Function (UDF) using cffunction that I want to use through out my web site.  I’ve tried placing the code in a cold fusion template that I place on every page (the same one where I reference the application tag), but I get a “function not defined” error.  I know the function works because when I place the code on a page that references it there are no errors.

So how exactly am I supposed to set this up?