https://magni-run.ru/sites/all/modules/scroll_to_top/scroll_to_top.js?tg76tx

1(function($){
2/**
3 * Toggle the visibility of the scroll to top link.
4 */
5 
6Drupal.behaviors.scroll_to_top = {
7  attach: function (context, settings) {
8	// append  back to top link top body if it is not
9	var exist= jQuery('#back-top').length; // exist = 0 if element doesn't exist
10	if(exist == 0){ // this test is for fixing the ajax bug 
11		$("body").append("<p id='back-top'><a href='#top'><span id='button'></span><span id='link'>" + settings.scroll_to_top.label + "</span></a></p>");
12	}
13	// Preview function
14	$("input").change(function () {
15		// building the style for preview
16		var style="<style>#scroll-to-top-prev-container #back-top-prev span#button-prev{ background-color:"+$("#edit-scroll-to-top-bg-color-out").val()+";} #scroll-to-top-prev-container #back-top-prev span#button-prev:hover{ background-color:"+$("#edit-scroll-to-top-bg-color-hover").val()+" }</style>"
17		// building the html content of preview
18		var html="<p id='back-top-prev' style='position:relative;'><a href='#top'><span id='button-prev'></span><span id='link'>";
19		// if label enabled display it
20		if($("#edit-scroll-to-top-display-text").attr('checked')){
21		html+=$("#edit-scroll-to-top-label").val();
22		}
23		html+="</span></a></p>";
24		// update the preview
25		$("#scroll-to-top-prev-container").html(style+html);
26	});
27	$("#back-top").hide();
28	$(function () {
29		$(window).scroll(function () {
30		// Adding IE8 support
31		  var scrollTop = 0;
32		  if (document.documentElement && document.documentElement.scrollTop) {
33			scrollTop = document.documentElement.scrollTop;
34		  }
35      if ($(this).scrollTop() > 100 || scrollTop > 100) {
36				$('#back-top').fadeIn();
37			} else {
38				$('#back-top').fadeOut();
39			}
40		});
41
42		// scroll body to 0px on click
43		$('#back-top a').click(function () {
44			$('body,html').animate({
45				scrollTop: 0
46			}, 800);
47			return false;
48		});
49	});
50	}
51};
52})(jQuery);