Finding orphan functions

Anyone have a suggestion for how I can determine if I have any orphan functions in a function file? I have a include file with about 30 functions that I have been adding to for several months. No doubt some have been superseded, etc. and are now obsolete. I could laboriously trace every path in my code and find the orphans; but, it would be nice to be able to automate the job a bit. Is there a neat way to run my applications and record which functions are used? Thanks....