My errors: Yes, typo HTML. Well, server-side PHP etc. is not too easy. The results you get by chopping up the browser window [replacing <BODY> tag] makes the whole page overly complicated and unwieldy.
Up until a year or so (when HTML5 became a hot topic), one of the professors teaching basic/beginner HTML where I tutor made students use <FRAMESET>. Made me so angry that he complicated HTML that way and students ended up with Web sites that did not function properly.
What effect do you want to achieve with <FRAMESET>? Do you have an online example to share? Maybe someone can suggest an alternative approach.
I for one don;t have the attitude or aptitude for AJAX coding.
P.S. -- Re-reading note your purpose is an HTML "tutorial." Imagine a very brief "footnote" reference to <FRAMESET> would suffice. Think it would be more helpful to point out how <FRAMESET> worked than whether or not it was "easier" than server-side scripting.