jquery setinterval

jquery setinterval

Hi i'm new to this post and i'm currently studying jquery. I have a jquery book and have been following it's examples to the T. but i've come across a problem when it talks about setinterval. The my coded example simply just doesn't work. I typed it word for word, letter for letter and it simply doesn't work. I've tried it in chrome and explorer, been trying to figure out a solution for some time now please help. Thanks.

Here is the js code:
  2. $(function(){
  3. var $green = $('#green');
  4. greenLeft = $green.offset().right;
  5. });
  6. $(function(){
  7. setInterval(function() {
  8. $green.css('left', ++greenLeft);
  9. }, 200);
  10. });

  12. $(function(){
  13. var $red = $('#red'),
  14. redLeft = $('#red').offset().left;
  15. function moveRed() {
  16. $red.css('left', ++redLeft);
  17. setTimeout(moveRed, 200);
  18. }
  19. moveRed();
  20. });
html code:
  2. <div id="green" class="box">Go!</div>
  3. <div id="red" class="box">Go!</div>
PS. All my plug-ins are there and correct because it works with other example