JavaScript

Unlike PHP, this runs in the browser — so it can change the page after it has already loaded.

1.1-example.html — Your first function

Attaching a function to a button's on-click.

2.2-loops.html — Loops

Using a loop to add content to the page.

3.3-changingSelects.html — Dynamic select boxes

Changing one dropdown based on what was picked in another.

_old/ holds earlier versions of these examples (countdowns, form changes, a deliberate syntax error). Ignore it unless you are told otherwise.