Forms Auth - Signoff User

Hi all.  Ok I am new to forms authentication and I am trying to pull this all together.  Right now I have a login page where if the user authenticates against a SQL Database then I move on and I am setting up a Forms Auth ticket etc.  I then have pages where I want to check certain credentials and if it does not pass or if the user just hits the page without authenticating to the SQL Database I want to force them to go back to the sign off page.  How do I do this.  I am posting here what I have.  I cant seem to get my global.asax page working so I added all this into the login page.   I will also paste my web.config.  At this point I dont know what to do etc.  Once the user authenticates from the SQL Database I pass to this method here:

private void ProcessFormsAuthentication(string USER_ID)
            {
                  FormsAuthentication.Initialize();
                  string roleList = GetRoles(USER_ID);

                  // Create the authentication ticket
                  FormsAuthenticationTicket authTicket = new
                        FormsAuthenticationTicket(1,                          // version
                        USER_ID,           // user name
                        DateTime.Now,               // creation
                        DateTime.Now.AddMinutes(60),// Expiration
                        false,                      // Persistent
                        roleList);                    // User data

                  // When the ticket was created, the UserData property was assigned a
                  // pipe delimited string of role names.
                  string[] roles = authTicket.UserData.Split(new char[]{'|'});
                  
                  // Create an Identity object
                  FormsIdentity id = new FormsIdentity(authTicket);

                  // This principal will flow throughout the request.
                  GenericPrincipal principal = new GenericPrincipal(id, roles);
                  // Attach the new principal object to the current HttpContext object
                  Context.User = principal;
                  
                  // Now encrypt the ticket.
                  string encryptedTicket = FormsAuthentication.Encrypt(authTicket);
                  // Create a cookie and add the encrypted ticket to the
                  // cookie as data.
                  HttpCookie authCookie =
                        new HttpCookie(FormsAuthentication.FormsCookieName,
                        encryptedTicket);

                  // Add the cookie to the outgoing cookies collection.
                  Response.Cookies.Add(authCookie);

                  Respones.Redirect("firstpage.aspx");
            }

            private string GetRoles(string USER_ID)
            {
                  return "Senior Manager|Manager|Employee";
                  //just for testing
            }

the roles is another issue I am looking at as well but I just want to also start with checking on a page the user is authenticated and playing around with a force sign off.   Here is my Web config.  I dont have any clue how the authorization works:

      <authentication mode="Forms">
                        <forms name="CustomerSite"
                              loginUrl="\Site\Logon.aspx"
                              protection="All"
                              timeout="60"
                              path="/"
                              requireSSL="true"
                              slidingExpiration="true">
                        </forms>
            </authentication>
            
            <authorization>
                  <allow users="*" />
            </authorization>