Question

This is an error in Firebug I keep seeing.

TypeError: $("#gallery-nav-button") is null
 [Break On This Error]  
$('#gallery-nav-button').addClass('animated fadeOutRightBig');

Here is my code:

JS

$(function() {
  $("#close-gallery-nav-button").click(function() {
    $('#gallery-nav-button').addClass('animated fadeOutRightBig');
   });
});

HTML

<div id="gallery-nav-button">
  <h4 id="close-gallery-nav-button">X</h4>
    <h3 class="text-center small-text"><a class="inline text-center small-text" href="#gallery-nav-instruct">Click Here for Gallery <br /> Navigation Instructions.</a></h3>
</div>

CSS

#close-gallery-nav-button{
  text-indent:-9999px; 
  width:20px; 
  height:20px; 
  position:absolute; 
  top:-20px; 
  background:url(/images/controls.png) no-repeat 0 0;
}
#close-gallery-nav-button{background-position:-50px 0px; right:0;}
#close-gallery-nav-button:hover{background-position:-50px -25px;}

Answer 1

I have several scripts running on this page and evidently one script was conflicting with another. To solve my issue I added jQuery.noConflict();

var $j = jQuery.noConflict();
$j(function() {
  $j("#close-gallery-nav-button").click(function() {
    $j('#gallery-nav-button').addClass('animated fadeOutRightBig');
   });
});