Help with Prestashop, which deletes content from cms page editor

I have a problem with my prestashop store: My coder (which isn't available anymore) implemented fancybox into galleries which i have in almost every cms page in the store. They all work well - fancybox has Next/Previous buttons, displays correctly. But when i try to create a new cms page with a new gallery and copy the code from any of already created pages, i received an error that the content is invalid, because all existing pages somehow contain <script>// <![CDATA[ $(document).ready(function() { $(".fancybox").fancybox({ openEffect : 'none', closeEffect : 'none' }); }); // ]]></script> while the editor does not allow scripts. But for some reason all the existing pages are valid this fancybox script implemented. Following these two tutorials tutorials http://tonalidad .es/blog-de-notas/galerias-en-prestashop-1-6-con-fancybox/ and http:// [login to view URL] I added the above script to my theme's [login to view URL] file, and now new images in the new gallery now appear in fancybox's frame, but they don't have a next/previous functions. I rechecked the html and noticed that the editor deletes the rel="" attribute from every image, which is supposed to group them. I checked all the front-office modules, thinking that maybe any of them generate the cms's content, but none of them seem to be involved. Thus images don't group, therefore i guess next/previous doesn't appear. That's my best guess but maybe i'm wrong. So, i need anyone who can fix and implement full galleries functionality, and explain me how to handle the cms content in the future to avoid such nonsence. Are you the man?