title: Stop nivo slider effect when some conditions occurs
body: <p>I don't want to slide nivo slider when the last image is focused.Example</p>
  
  <pre><code>$('#slider').nivoSlider({
      manualAdvance: true,
      beforeChange: function(){
          if(condition){
             //do not go to afterChange function
          }
      },
      afterChange: function(){
  
      }, 
  });
  </code></pre>
  
  <p>Can i stop the slider from sliding?</p>