I got this issue while checking the script code with Chrome.
Here is the code in question :
if (!!$.prototype.fancybox)
$.extend($.fancybox.defaults.tpl, {
var FancyboxI18nClose = 'CloseBtn';
var FancyboxI18nNext = 'Next';
var FancyboxI18nPrev = 'Prev';
closeBtn : '<a title="' + FancyboxI18nClose + '" class="fancybox-item fancybox-close" href="javascript:;"></a>',
next : '<a title="' + FancyboxI18nNext + '" class="fancybox-nav fancybox-next" href="javascript:;"><span></span></a>',
prev : '<a title="' + FancyboxI18nPrev + '" class="fancybox-nav fancybox-prev" href="javascript:;"><span></span></a>'
});
The problematic line is
var FancyboxI18nClose = 'CloseBtn';