js對cookie的寫入，讀取及刪除方法

    這里的js對cookie的寫入，讀取及刪除方法，都很實用:
    /*
    name:cookie 名
    value:cookie 值
    */
    //寫入cookie
    function SetCookie(name,value)
    {
    var Days = 30; //此 cookie 將被保存 30 天
    var exp = new Date();
    exp.setTime(exp.getTime() + Days*24*60*60*1000);
    document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
    }
    ///刪除cookie
    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();
    }
    //讀取cookie
    function getCookie(name)
    {
    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));
    if(arr != null)
    return unescape(arr[2]);
    return null;
    }