为什么COOKIE清除不了？

Question

region 退出登录
private void logout_Click(object sender, System.EventArgs e)
{
if(Request.Cookies["lcbbs"]!=null)
{
Session.Remove("username");
Session.Remove("userlevel");
HttpCookie cookie=Request.Cookies["lcbbs"];
cookie.Expires=DateTime.Now.AddDays(-1);
cookie.Values.Clear();
LoadLogin();
}
}
# endregion

Answer 1

cookie.Expires=DateTime.MinValue
Response.Cookies.Set(httpCookie);