The JavaScript::

1. var $ = function(id) {

2. return document.getElementById(id);

3. };

4. var timer;

5. var counter = 10;

6. var updateCounter = function() {

7. counter--;

8. $("counter").firstChild.nodeValue = counter;

9. if (counter <= 0) {

10. clearInterval(timer);

11. document.getElementById("counter").innerHTML = "Blastoff!";

12. }

13. };

14. window.onload = function() {

15. timer = setInterval ( updateCounter, 1000 );

16. };

The HTML:

Countdown: 10

The timer in this code will update the counter???