Rule One - XML Documents need a root element.
For web pages this is the <html> and </html> element pair.
The very first thing on the page (after the DOCTYPE which we will be talking about soon) should be the root element of the page or <html>.
And the last element on the page should be </html>.
That means that anything after the </html> element can be ignored by the browser.
Now, that may not happen with FireFox or Internet Explorer, but keep in mind you are writing for all browsers including those tiny browsers on your cell phone that don't have enough room in their program code to check for all types of coding exceptions. If content is put after the </html> it is simply dropped.
