研究一下yahoo的酷图幻灯js代码

    js代码如下：

    var PUisIE_NAV4 = false;
    if (parseFloat(navigator.appVersion) >= 4) {
    PUisIE_NAV4 = true;
    }

    var PUwinWidth='740';
    var PUwinHeight='320';

    var PUtimes = 1; /* number of times to show ad. if > times, then redirect thru */
    //var PUtheDomain = ".cn.yahoo.com";
    var PUtheDomain = document.domain;
    var PUeXPiresIn = 4/24; /* days between shows of the ad */

    function errorsuppressor(){
    return true
    }
    window.onerror=errorsuppressor;

    function PUsetCook(t,expIn) {
    var cook;
    var PUexDate;
    PUexDate = new Date;
    PUexDate.setTime(PUexDate.getTime() + expIn*24*60*60*1000);
    cook = "PU=t="+t+"; expires=" + PUexDate.toGMTString() +"; domain="+PUtheDomain + "; path=/";
    document.cookie = cook;
    }

    var PU_NO_COOKIES = 9999;

    function PUgetCook(x) {
    var i,j,a,b,s,e,d,f;
    a = document.cookie;
    if (a == "") return PU_NO_COOKIES;
    s = a.indexOf(x + "=");
    if (s == -1) return false;
    s += x.length+1;
    e = a.indexOf(';',s);
    if (e == -1) e = a.length;
    return a.substring(s,e);

    }

    /* check cookies - if cookies are off or if user saw it X times, then we redirect thru */

    var PUd;
    var PUb=PUgetCook("PU");
    var PUoverTimes = 0;

    if (PUb == PU_NO_COOKIES) {
    PUoverTimes = 1;
    } else {
    if (PUb != false) {
    PUb = PUb.split('&');
    for (PUi=0; PUi<PUb.length; PUi++) {
    PUd = PUb[PUi].split('=');
    if (PUd == "t") {
    last;
    }
    }
    PUd[1]++;
    if (PUd[1] > PUtimes) {