templates = better performance???

Hi, I'm working on a web site that has a common header,navigation links, and footer.

I'm thinking of just writing 3 funtions:
function header()
function navigation()
function footer ()

and saving them on a common file (something like functions.php)

Then calling the functions in each page?

Will this affect how fast the web page loads?
Will it take longer for the page to load since it has to get part of the page from another file (functions.php)?

I've read a lot of stuff on templates (www.phpbuilder.com), but I think just using functions will work fine for me since I'm not expecting to do anything too fancy with the page.

Thanks

Mike

Yes, there is a very small performance hit due to additional filesystem accesses. Template constructs have an even bigger performance hit, though. It's a give and take between performance and ease of modification.