Show one div and hide others div

<a href="#" rel="week_3">Week 3</a>

<a href="#" rel="week_4">Week 4</a>

<div>
    <div id="week_3" style="display: none">[..xz.]</div>
    <div id="week_4" style="display: none">[...]</div>
</div>

$('a').on('click', function(){
   var target = $(this).attr('rel');
   $("#"+target).show().siblings("div").hide();
});