Hi,

I am working in a Login page and teh logic is like ->

try { DirectoryEntry LDAPLogin = new DirectoryEntry(ConfigurationSettings.AppSettings ["LDAPPath"].ToString(), Usuario, Txt_Contrasenia.Text.ToString());

        if (LDAPLogin.NativeGuid != LDAPLogin.Name)
            ValidarGrupo();

    }
    catch (Exception exc)
    {
        Label_Info.Text = "Sus credenciales no son validas: " + Usuario.ToString() + " " + exc.Message;
    }

If the user enters the rights credentials I call a method ValidarGrupo that implements a lookup in the AD for a group of the user

I woould like to replace the username and password with UseDefaultCredentials in order to avoid that the user has to enter the username and password and the Login pages use the credentials of the user that is login on the machine.