jquery滚动保持定位层
本插件借鉴了一些网上的资料，实际运用可以自行修改。
/*! * jQuery scrollsPosition plugin * jquery滚动保持定位层 * Copyright (c) 2012 Geetaku * * @author JSCZXY2 * */$.fn.scrollsPosition = function() {var position = function(element) {element.css("z-index","999");var top = element.position().top, pos = element.css("position");$(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 {if(pos == "relative"){element.css({position: pos,});}else{element.css({position: pos,top: top});}}});};return $(this).each(function() {position($(this)); });};