//保存cookies
function setCookie(name, value) {
    var Days = 30;
    var exp = new Date();    //new Date("December 31, 9998");
    exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);
    document.cookie = name + "=" + escape(value) + ";expires=" + exp.toGMTString();
    
}

//取cookies
function getCookie(name) {
    var arr, reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");
    if (arr = document.cookie.match(reg))return unescape(arr[2]);
    else{ return null;}
   
}

//删除cookies
function delCookie(name) {
    var exp = new Date();
    exp.setTime(exp.getTime() - 1);
    var cval = getCookie(name);
    if (cval != null) document.cookie = name + "=" + cval + ";expires=" + exp.toGMTString();
}