function GetMyCookieVal(offset)
        //获得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));
        }
        function DelMyCookie(name)
        //删除Cookie
        {
            var exp = new Date();
            exp.setTime (exp.getTime() - 1);
            var cval = GetMyCookie (name);
            document.cookie = name + "=" + cval + "; expires="+ exp.toGMTString();
        }
        
        function GetMyCookie(name)
        //获得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 GetMyCookieVal (j);
            i = document.cookie.indexOf(" ", i) + 1;
            if (i == 0) break;
            }
            return null;
        }
        
         function SaveMyCookie(name,value)
        {
            var Days = 30;
            var exp = new Date(); 
            exp.setTime(exp.getTime() + Days*24*60*60*1000);
            document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
        }