Thank you very much for your kind reply,Daniel0. It is very helpful to me.
What I intend to do is do it in a modular fashion, with MVC pattern, ya, but I don't want to try the template engines like cakephp, smarty, etc. I would to create one on my own, also to cater for my own needs.
Ok, let's say, in my template, there will be head section, menu section,sidebar section,main content section,footer section,etc,what I am trying to do now is to build a separate .tpl file for each section, but with customizable functionality, i.e. when applying the template head, I shall be able to specify the title of the page.
What do you think of my approach? Any suggestions? It is still in my mind, I haven't have clear thoughts how to realize it in codes. So inputs would be greatly appreciated!