$(document).ready(function() {// jQuery SmoothScroll | Version 09-11-02
$('a#back-top').click(function() {

   // duration in ms
   var duration=1000;

   // easing values: swing | linear
   var easing='swing';

   // get / set parameters
   var newHash=this.hash;
   var target=$(this.hash).offset().top;
   var oldLocation=window.location.href.replace(window.location.hash, '');
   var newLocation=this;

   // make sure it's the same location      
   if(oldLocation+newHash==newLocation)
   {
      // animate to target and set the hash to the window.location after the animation
      $('html:not(:animated),body:not(:animated)').animate({ scrollTop: target }, duration, easing, function() {

         // add new hash to the browser location
         window.location.href=newLocation;
      });

      // cancel default click action
      return false;
   }

});});