function tips_pop() {
    var MsgPop = document.getElementById("winpop");
    var popH = parseInt(MsgPop.style.height); //将对象的高度转化为数字
    if (popH == 0) {
        MsgPop.style.display = "block"; //显示隐藏的窗口
        show = setInterval("changeH('up')", 2);
    }
    else {
        hide = setInterval("changeH('down')", 2);
    }
}
function changeH(str) {
    var MsgPop = document.getElementById("winpop");
    var popH = parseInt(MsgPop.style.height);
    if (str == "up") {
        if (popH <= 200) {
            MsgPop.style.height = (popH + 4).toString() + "px";
            MsgPop.style.top = window.screenTop+300;
        }
        else {
            clearInterval(show);
        }
    }
    if (str == "down") {
        if (popH >= 4) {
            MsgPop.style.height = (popH - 4).toString() + "px";
        }
        else {
            clearInterval(hide);
            MsgPop.style.display = "none";  //隐藏DIV
        }
    }
}
window.onload = function() {    //加载
    document.getElementById('winpop').style.height = '0px';
    setTimeout("tips_pop()", 800);     //3秒后调用tips_pop()这个函数
}