deBugging...

deBugging...

This function worked fine in a test page, but it's dead in a new local page: Firefox is throwing 
"(jQuery) not defined'  in:

(function($){
      $.fn.visibility = function(status) {
            this.css('visibility',status);
            return this;
      }
})(jQuery)

$(document).ready(function(){
$('.hex').hover(function(){
$(this).find('.hN').visibility('visible'); 
});
$('.hex2').hover(function(){
$(this).find('.hN').visibility('visible'); 
});
$('.hex').click(function() {
      $(this).animate({color:"#777"}, 400);
            $(this).animate({color:"#555"}, 800);
});
});

Any pointers to debugging: I've spent a few hours already...