//写cookies
        
        function setCookieDo(name,value)
        {
            var Days = 1;
            var exp = new Date();
            exp.setTime(exp.getTime() + Days*6*60*60*1000);
            document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString() + ";path = /";
        }
        
        //读取cookies
        function getCookieDo(name)
        {
            var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
         
            if(arr=document.cookie.match(reg))
         
                return unescape(arr[2]);
            else
                return null;
        }
        
        //删除cookies
        function delCookieDo(name)
        {
            var exp = new Date();
            exp.setTime(exp.getTime() - 1);
            var cval=getCookie(name);
            if(cval!=null)
                document.cookie= name + "="+cval+";expires="+exp.toGMTString();
        }