title: How to make slow the Scroll-Top Speed
body: <p>ScrollTop is a jquery plugin <em>(go to top of page)</em>, trying to make slow Scroll Speed, but not working. I have changed <code>scrollSpeed : 'fast',</code> to <code>scrollSpeed : 'slow',</code> but it still fast, nothing change.</p>
  
  <p><strong>JS:</strong></p>
  
  <pre><code>$.fn.extend({
  
      addScrollTop: function(options) {
  
          var defaults = {
                  useObjWindow : false,
                  scrollSpeed : 'fast',
                  zIndex: '99'
              }
  
              var options = $.extend(defaults, options);  
  
          if($('body').find('.scrollTop-btn').length == 0) {
              $('body').append('&lt;div class="scrollTop-btn" style="display:none;"&gt;&lt;i class="fa fa-chevron-up"&gt;&lt;/i&gt;&lt;/div&gt;');
          }
  
          if(options.useObjWindow) {
              var parentWindow = this;
              var scrollWindow = this;
          }
          else {
              var parentWindow = window;
              var scrollWindow = 'html, body';
          }
  
          $(document).ready(function() {
  
              $('.scrollTop-btn').on('click', function() {
                  $(scrollWindow).animate({scrollTop:0}, options.scrollSpeed);
              });
  
              $(parentWindow).scroll(function() { 
                  $('.scrollTop-btn').hide();
                  var aTop = $('.scrollTop-btn').height() + 20;
  
                  if($(this).scrollTop() &gt;= (aTop + 20)) {
                      $('.scrollTop-btn').css('z-index', options.zIndex);
                      $('.scrollTop-btn').show();
                  }
                  else {
                      if($('.scrollTop-btn').is(":visible")) {
                          $('.scrollTop-btn').hide();
                      }
                  }
  
              });
  
  
          });
      }
  
  });
  </code></pre>
  
  <p><strong>Call:</strong></p>
  
  <pre><code>jQuery(document).ready(function() {
  jQuery("body").addScrollTop();
  });
  </code></pre>
  
  <p>How to make it slower or smoother, when it go to top?</p>