jquery code not working in chrome, but works in IE and FF

jquery code not working in chrome, but works in IE and FF

I was under the impression that jquery is cross browser. For some reason in chrome when I click my button, nothing happens. this works in FF and IE though. any ideas?

[yes, this code is extremely ugly and not proficient, but it works in IE/FF. I just started learning jquery, so please be kind :) ]

  1.      $(document).ready(function() {
  2.           $('.extra_btn').click(function() {
  3.                $('.extra_btn').fadeOut('fast');
  4.           });
  5.           $('.extra_btn').click(function() {
  6.                $('.extra_form').fadeIn('slow');
  7.           });
  8.           $('.extra_btn').click(function() {
  9.                 $(".jquery-lightbox-html, .jquery-lightbox-mode-html").animate(
  10.                     {"height": "680px"},
  11.                     "fast");
  12.                 });
  13.           $('.extra_btn').click(function() {
  14.                 $(".jquery-lightbox-background").animate(
  15.                     {"height": "688px"},
  16.                     "fast");
  17.                 });
  18.           $('.extra_btn').click(function() {
  19.                 $(".jquery-lightbox").animate(
  20.                     {"height": "670px"},
  21.                     "fast");
  22.                 });
  23.      });