Here's a handy template. I don't use this for actual web pages (altho you could) but it is perfect for doing quick experiments on your local machine.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
window.onload = function()
Ok, enough of that
1. What is the basic meaning of the terms "syntax" and "semantics"?
2. What is an "identifier" or "variable"?
3. What is an "expression" and what does it mean to "evaluate" an expression?