用 Javascript和JQuery 操作 Cookie

// ===========Javascript====================

//建立一個cookie    
function createCookie(name,value,days) {
 if (days) {
  var date = new Date();
  date.setTime(date.getTime()+(days*24*60*60*1000));
  var expires = "";
  expires=""+date.toGMTString();
 }
 else var expires = "";
 document.cookie = name + "=" + value + "; expires=" + expires;  

}

//讀取cookie
function GetCookie(name)
//讀取Cookie的原始值
{
    var arg = name + "=";
    var alen = arg.length;
    var clen = document.cookie.length;
    var i = 0;
    while (i < clen) {
        var j = i + alen;
        if (document.cookie.substring(i, j) == arg)
            return GetCookieVal(j);
        i = document.cookie.indexOf(" ", i) + 1;
        if (i == 0) break;
    }
    return null;
}

function GetCookieVal(offset)
//獲得Cookie解码后的值
{
    var endstr = document.cookie.indexOf(";", offset);
    if (endstr == -1)
        endstr = document.cookie.length;
    return unescape(document.cookie.substring(offset, endstr));
}


//刪除cookie
function DeleteCookie(name) {
 createCookie(name,"",-1);
}

// ===========JQuery====================

<script src="/Scripts/jQuery.cookie.js" type="text/javascript"></script>

<script type="text/javascript">
    //設定Cookie，5天後過期，如果不設定時間就是瀏覽器關掉就不見
    $.cookie('welkin_cookie', 'myValue', { path:'/', expires: 5 });                   

    //設定Cookie，同樣也是5天後過期，用毫秒表示           
    var date = new Date();
    date.setTime(date.getTime() + (5 * 24 * 60 * 60 * 1000));
    $.cookie('welkin_cookie', 'myValue', { path:'/', expires: date });

    //取得Cookie的值，若無則返回null
    $.cookie('welkin_cookie');

    //刪除Cookie
    $.cookie(COOKIE_NAME, null, { path: '/', expires: 5 });
    //或
    $.cookie('welkin_cookie', null);
    //或
    $.cookie('welkin_cookie', { expires: -1 });
 
</script>