window.onbeforeunload = function () {
var scrollPos;
if (typeof window.pageYOffset != 'undefined') {
scrollPos = window.pageYOffset;
}
else if (typeof document.compatMode != 'undefined' &&
document.compatMode != 'BackCompat') {
scrollPos = document.documentElement.scrollTop;
}
else if (typeof document.body != 'undefined') {
scrollPos = document.body.scrollTop;
}
document.cookie = "scrollTop=" + scrollPos; //存储滚动条位置到cookies中
}

window.onload = function () {
if (document.cookie.match(/scrollTop=([^;]+)(;|$)/) != null) {
var arr = document.cookie.match(/scrollTop=([^;]+)(;|$)/); //cookies中不为空，则读取滚动条位置
document.documentElement.scrollTop = parseInt(arr[1]);
document.body.scrollTop = parseInt(arr[1]);
}
}