javascript中cookie的读写以及删除

<script language="Javascript">

function setCookie(name,value)

{

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)

{

var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");

if(arr=document.cookie.match(reg)) return unescape(arr[2]);

else return null;

}

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();

}

setCookie("user","looping");

user=getCookie("user");

if(user==null) alert("no cookie");

else document.write(user);

</script>