THIS CODE UNDER HERE WORKS, you can read the answers under here - i edit this for future reference.

HTML:

<div><a href=# id=btn>Show bank div and hide fancy div</a></div>

<div id=btn-bk><a href=#>back</a></div>

<div id=bank>Bank Div</div>

<div id=fancy>Fancy Div</div>

CSS:

#bank {display:none;}

#btn-bk {display:none;}

Javascript:

    $('#btn').click(function(e){    

    $('#fancy, #btn').fadeOut('slow', function(){

        $('#bank, #btn-bk').fadeIn('slow');

    });

});



    $('#btn-bk').click(function(e){    

        $('#bank, #btn-bk').fadeOut('slow', function(){

            $('#fancy, #btn').fadeIn('slow');

        });

    });

Live DEMO that works