Fatal error: Call to undefined function htmlout()

I’m working from kevin yanks book and I recieve this error when inserting the code from p211.

I don’t have that book. So unless you give more info, and some code, I won’t be able to help you.
Anyway, the message is very clear: you are trying to use a function (htmlout) that doesn’t exist.

I am unfamiliar with the code you’re referring to, but there are several things that could cause an undefined error.

If the function is in another file, is the spelling and path used to get it OK and permissions set to allow access?

In the function itself, does it have the correct syntax (eg. paired curly braces, statement terminators, etc.)?

I had this problem myself and found if was because the “htmlout” method defined in the helpers.inc.php was not being included.