Button script, yes; BOI script no.  When "compiled" each BOI script gets wrapped inside a sub, and you can't have a function inside a sub.

That makes sense, i want to create and event based on a UDF column (end date).

I cannot even save the script because i get a syntax error....

Thanks Kevin, I appreciate your prompt response 

There is a way around this. Structure the script like this:

End Sub ' this will cause the end of the sub started in the wrapper Kevin refers to 

Function myFunction

...

End Function

Sub myFix  ' this will be ended by the End Sub created by the wrapper.