cookie and sliding expiration

i use the following code in the Page_Load event in all of the *.aspx.cs pages to slide the expiration date of the cookie. it works but i just have to include in all of the pages. is there a better or the correct way to slide the expiration of the cookie? private void Page_Load(object sender, System.EventArgs e) { HttpCookie cookie = Request.Cookies.Get(FormsAuthentication.FormsCookieName); cookie.Expires = DateTime.Now + new TimeSpan (0, 0, 30, 0); Response.Cookies.Set(cookie); }