Orange changed their field names.

orangelogin.pl

@@ -46,8 +46,8 @@ print "Logging in\n";
 $mech->submit_form(
 	form_number => 1,
 	fields      => {
-		txtMSISDN  => $username,
-		txtPassword  => $password,
+		LOGIN     => $username,
+		PASSWORD  => $password,
 	}
 );