<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/fancybox/2.1.4/jquery.fancybox.pack.js"></script>
<script>
$(function() {
  $('.entry-content').each(function(i){
    var _i = i;
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        img.parent().attr("title", title);
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  $('.fancybox').fancybox();
});
</script>