<script language="javascript">
       //写cookies
       function setCookie(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();
       }       
       //读取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();
        }
 </script>  

document.write(document.cookie);//输出类似"name1=value1; name2=value2; name3=value3"的字符串
document.write(typeof document.cookie);//cookie仅仅是个字符串

<script language=javascript>

//获得coolie 的值

function cookie(name){   

   var cookieArray=document.cookie.split("; "); //得到分割的cookie名值对   

   var cookie=new Object();   

   for (var i=0;i<cookieArray.length;i++){   

      var arr=cookieArray[i].split("=");       //将名和值分开   

      if(arr[0]==name)return unescape(arr[1]); //如果是指定的cookie，则返回它的值   

   }

   return "";

}

function delCookie(name)//删除cookie

{

   document.cookie = name+"=;expires="+(new Date(0)).toGMTString();

}

function getCookie(objName){//获取指定名称的cookie的值

    var arrStr = document.cookie.split("; ");

    for(var i = 0;i < arrStr.length;i ++){

        var temp = arrStr[i].split("=");

        if(temp[0] == objName) return unescape(temp[1]);

   }

}

function addCookie(objName,objValue,objHours){      //添加cookie

    var str = objName + "=" + escape(objValue);

    if(objHours > 0){                               //为时不设定过期时间，浏览器关闭时cookie自动消失

        var date = new Date();

        var ms = objHours*3600*1000;

        date.setTime(date.getTime() + ms);

        str += "; expires=" + date.toGMTString();

   }

   document.cookie = str;

}

function SetCookie(name,value)//两个参数，一个是cookie的名子，一个是值

{

    var Days = 30; //此 cookie 将被保存 30 天

    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();

}

function getCookie(name)//取cookies函数       

{

    var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));

     if(arr != null) return unescape(arr[2]); return null;

}

function delCookie(name)//删除cookie

{

    var exp = new Date();

    exp.setTime(exp.getTime() - 1);

    var cval=getCookie(name);

    if(cval!=null) document.cookie= name + "="+cval+";expires="+exp.toGMTString();

}

</script>