protected void ctlLogin_LoggedIN(object sender, EventArgs e)
    {
        CheckBox rm = (CheckBox)ctlLogin.FindControl("RememberMe");
        if (rm.Checked)
        {
            HttpCookie myCookie = new HttpCookie("myCookie");
            Response.Cookies.Remove("myCookie");
            Response.Cookies.Add(myCookie);
            myCookie.Values.Add("username", this.ctlLogin.UserName.ToString());
            DateTime dtExpiry = DateTime.Now.AddDays(15); //you can add years and months too here
            Response.Cookies["myCookie"].Expires = dtExpiry;
        }
        else
        {
            HttpCookie myCookie = new HttpCookie("myCookie");
            Response.Cookies.Remove("myCookie");
            Response.Cookies.Add(myCookie);
            myCookie.Values.Add("username", this.ctlLogin.UserName.ToString());
            DateTime dtExpiry = DateTime.Now.AddSeconds(1); //you can add years and months too here
            Response.Cookies["myCookie"].Expires = dtExpiry;
            

        }


    }

This function is called after the applicaton verifies that the user is a valid user and is logged in.  I tried to just remove the cookie if the checkbox wasn't checked, but it didn't seem to be working, so I just give it a very short expiration date to get rid of it. 

Once again..thanks for any help!

Greg