[Koha] How to add code to Marc record and display it in opac?

Hi everyone. Someone tried to add code of embed book to marc record and display it in the opac html5 media player? I have an idea to convert the first pages of books into flipbooks ( www.anyflip.com) and put code in marc record to be able to read them in opac media player. For example I would like to add this code: <iframe style="width:550px;height:350px" src=" http://online.anyflip.com/mepon/fath/" seamless="seamless" scrolling="no" frameborder="0" allowtransparency="true" allowfullscreen="true" ></iframe> to marc record of some book in 856u field, but in opac i see only code, I don't see frame with flip book. help me please realize this idea Paolo -- З повагою Павло Бобесюк=))