https://www.jianghan.gov.cn/material/scripts/manhuatotop.js

1// JavaScript Document
2jQuery(function() {
3	jQuery.fn.manhuatoTop = function(options) {
4		var defaults = {			
5			showHeight : 150,
6			speed : 1000
7		};
8		var options =jQuery.extend(defaults,options);
9		jQuery("body").prepend("<div id='totop'><a></a></div>");
10		var $toTop = jQuery(this);
11		var $top = jQuery("#totop");
12		var $ta = jQuery("#totop a");
13		$toTop.scroll(function(){
14			var scrolltop=jQuery(this).scrollTop();		
15			if(scrolltop>=options.showHeight){				
16				$top.show();
17			}
18			else{
19				$top.hide();
20			}
21		});	
22		$ta.hover(function(){ 		
23			jQuery(this).addClass("cur");	
24		},function(){			
25			jQuery(this).removeClass("cur");		
26		});	
27		$top.click(function(){
28			jQuery("html,body").animate({scrollTop: 0}, options.speed);	
29		});
30	}
31});