【JS】滚动吸顶

smartFloat.js

	// 时间倒数吸顶
	$.fn.smartFloat = function() {
		var position = function(element) {
		  var top = element.position().top, pos = element.css("position");
		  $(window).scroll(function() {
		      var scrolls = $(this).scrollTop();
		      if (scrolls > top) {
		          if (window.XMLHttpRequest) {
		              element.css({
		                  position: "fixed",
		                  top: 0
		              });    
		          } else {
		              element.css({
		                  top: scrolls
		              });    
		          }
		      }else {
		          element.css({
		              position: "absolute",
		              top: top
		          });    
		      }
		  });
		};
		return $(this).each(function() {
		  position($(this));                         
		});
	};

	$("#timeLeft").smartFloat();