js操作cookie

//写入cookie
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();
}