js get/set Cookie

 <script language= "javascript"  >
 function  setCookie(name,value)
 {
 /*
 *--------------- setCookie(name,value) -----------------
 * setCookie(name,value)
 * 功能:设置得变量name的值
 * 参数:name,字符串;value,字符串.
 * 实例:setCookie('username','baobao')
 *--------------- setCookie(name,value) -----------------
 */
 var  Days = 30;  //此 cookie 将被保存 30 天
　　 var  exp　=  new  Date();
 exp.setTime(exp.getTime() + Days*24*60*60*1000);
 document.cookie = name +  "=" + escape (value) +  ";expires="  + exp.toGMTString();
 }

</script>

<script language= "javascript"  >
function  getCookie(name)
{
/*
*--------------- getCookie(name) -----------------
* getCookie(name)
* 功能:取得变量name的值
* 参数:name,字符串.
* 实例:alert(getCookie("baobao"));
*--------------- getCookie(name) -----------------
*/

var  arr = document.cookie.match( new  RegExp( "(^| )" +name+ "=([^;]*)(;|$)" ));
if (arr !=  null )  return  unescape(arr[2]);  return  null ;
}
</script>