...cut...
<authentication mode="Forms">
   <forms loginUrl="logon.aspx" name="pidCookie" timeout="60" path="/" />
</authentication>
<authorization>
   <deny users="?"/>
   <allow users="*"/>
</authorization>
...cut...

procedure TWebForm1.btnLogin_Click(sender: System.Object; e: System.EventArgs);
begin
 //cut user authentication 
 FormsAuthentication.RedirectFromLoginPage(tbxUser.Text, false);
end;

procedure TWebForm1.btnLogOut_Click(sender: System.Object; e: System.EventArgs);
begin
 FormsAuthentication.SignOut;
end;

procedure TWebForm1.btnLogin_Click(sender: System.Object; e: System.EventArgs);
begin
 FormsAuthentication.RedirectFromLoginPage(tbxUser.Text, false);
end;

k_2>Все работает на localhost и не работает в интранете

<authentication mode="Forms">
   <forms loginUrl="logon.aspx" name="pid_auth_1" timeout="60" path="/pid_app_1" />
</authentication>

  TUsers = class
  private
    FUserFile: string;
  public
    constructor Create(path: string);
    function GetUserDetails(const UserName : string): TUsersDetails;
    function Login(const UserName, Password : String): boolean;
  end;

procedure TWebForm1.btnLogin_Click(sender: System.Object; e: System.EventArgs);
var
 u: TUsers; 
begin
 u := TUsers.Create(Server.MapPath('./bd_xml/UsersDB.xml'));
 try
  if u.Login(tbxUser.Text, tbxPassword.Text) then 
    FormsAuthentication.RedirectFromLoginPage(tbxUser.Text, false)
  else 
    msg.text := 'Што то грозное' //msg - asp:label на login
 finally
  u.free
 end; 
end;

k_2>>Все работает на localhost и не работает в интранете

D>Насколько я понял, то не работает не все, а именно процедура входа после выхода.

D>На серваке, на котором все неработает стоит один экземпляр приложения?

D><authentication mode="Forms">
D>   <forms loginUrl="logon.aspx" name="pid_auth_1" timeout="60" path="/pid_app_1" />
D></authentication>
D>

var
  hc: HttpCookie;
  ts: TimeSpan;
begin
hc := FormsAuthentication.GetAuthCookie(tbxUser.Text, false);
ts := TimeSpan.Create(1,0,0,0);
hc.Expires := DateTime.Now.Add(ts);
Response.Cookies.Add(hc);...

k_2>Смена оси не помогла, а изменение имени компьютера сработало

host
The fully qualified domain name of a network host, or its IP
address as a set of four decimal digit groups separated by
".". Fully qualified domain names take the form as described
in Section 3.5 of RFC 1034 [13] and Section 2.1 of RFC 1123
[5]: a sequence of domain labels separated by ".", each domain
label starting and ending with an alphanumerical character and
possibly also containing "-" characters. The rightmost domain
label will never start with a digit, though, which
syntactically distinguishes all domain names from the IP
addresses.

<domain> ::= <subdomain> | " "
<subdomain> ::= <label> | <subdomain> "." <label>
<label> ::= <letter> [ [ <ldh-str> ] <let-dig> ]
<ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
<let-dig-hyp> ::= <let-dig> | "-"
<let-dig> ::= <letter> | <digit>

<letter> ::= any one of the 52 alphabetic characters A through Z in
upper case and a through z in lower case
<digit> ::= any one of the ten digits 0 through 9

The labels must follow the rules for ARPANET host names. They must
start with a letter, end with a letter or digit, and have as interior
characters only letters, digits, and hyphen. There are also some
restrictions on the length. Labels must be 63 characters or less.

k_2>спасибо