//ulroll
var ulroll = function(id, dir, vt) {
    var scrollbox = document.getelementbyid(id); //滚动外层遮挡框架
    if (!scrollbox) return false;
    var oldcontent = scrollbox.getelementsbytagname("ul")[0]; //ul index=0;
    if (!oldcontent) return false;
    var domeone = scrollbox.getelementsbytagname("li"); // li
    if (!domeone.length) return false;
    var domeonelen = domeone.length;
    var oldlong = 0; //旧总长
    var newlong = 0; //新总长-外层框架长度
    var newcontent = oldcontent.innerhtml;
    if (dir == "1") {
        for (var i = 0; i < domeonelen; i++) {
            oldlong += domeone[i].offsetwidth;
        }
        while (newlong < (scrollbox.offsetwidth)) {
            newcontent += oldcontent.innerhtml;
            newlong += oldlong;
        }
    } else if (dir == "2") {
        for (var i = 0; i < domeonelen; i++) {
            oldlong += domeone[i].offsetheight;
        }
        while (newlong < (scrollbox.offsetheight)) {
            newcontent += oldcontent.innerhtml;
            newlong += oldlong;
        }
    } //判断新ul的总长
    oldcontent.innerhtml = newcontent; //生成新的ul
    var dometwo = scrollbox.getelementsbytagname("li")[domeonelen]; //滚动结束位置
    var myroll = function() {
        if (dir == "1") {
            if (scrollbox.scrollleft == dometwo.offsetleft) {
                scrollbox.scrollleft = 0;
            } else {
                scrollbox.scrollleft++;
            }
        } else if (dir == "2") {
            if (scrollbox.scrolltop >= dometwo.offsettop) {
                scrollbox.scrolltop = 0;
            } else {
                scrollbox.scrolltop++;
            }
        }
    } //滚动
    var timer = setinterval(myroll, vt); //周期性调用滚动
    scrollbox.onmouseover = function() { clearinterval(timer) }
    scrollbox.onmouseout = function() { timer = setinterval(myroll, vt) }
} // id=最外层遮挡框架id ,滚动方式dir=1，2 分别对应左 上,vt滚动速度；