关于网站cookie的读取，写入，清楚！

写cookie

HttpCookie UserCookie = new HttpCookie("userName");
UserCookie["name"]=dr["user"].ToString();

UserCookie.Expires=DateTime.Now.AddDays(1);//这里设置要保存多长时间.
Response.Cookies.Add(UserCookie);

读取cookie

HttpCookie cookie=Request.Cookies["userName"];
string name=cookie.Values["name"];

清除cookie

HttpCookie cookie=Request.Cookies["userName"];
if(cookie!=null)
{
cookie.Expires=DateTime.Now.AddDays(-2);
Response.Cookies.Set(cookie);
}