title: add and remove css for z-index dynamically
body: <p><code>$('.sn').css({'z-index':'-1000'});</code>
   (hide whole group) on load whole class, and from that class i want to show or appy css    <code>$('#item1').css({'z-index':'1000'});</code>(show only one from the group) on click of some element dynamicaly but this do not happen pls help me?
  and when i use hide() &amp; show() methods it works fine.</p>
  
  <pre><code>//on click ..
  $(document).on('click','#slider1prev',function(){   
  
      selected = selected-1;
  
  
  
      if(my_text != ""){
          $('#noteImage'+selected).css({'z-index':'1000'});
          $('#noteText'+selected).css({'z-index':'1000'});
      }
  
  });
  </code></pre>
  
  <p>//onload..</p>
  
  <pre><code>$('.sn').css({'z-index':'-1000'});
  $('.notes').css({'z-index':'-1000'});
  </code></pre>