table of content type mismatch error

I've created a table of contents table with the article "How to Create..."
Now I'm getting an error msg "The expression OnPrint entered as event
property setting produced following error: Type mismatch. *Expression may
not result in name of macro, function ro event procedure. *There may have
been error evalutaing function, event or macro."

As I'm new to code and am not quite sure where all should be placed, I'm
hoping someone can help correct this error.

Thanks in advance for any much needed help.
Pam