AddJS() don't execute

[hph]

procedure TUniServerModule.UniGUIServerModuleHTTPCommand(
  ARequestInfo: TIdHTTPRequestInfo; AResponseInfo: TIdHTTPResponseInfo;
  var Handled: Boolean);
var
  sid: TUniGUISession;
  ActiveSessions : TUniGUISessions;
  I : Integer;
begin
  if ARequestInfo.URI='/test/send' then
  begin
    SessionManager.Sessions.Lock;
    ActiveSessions := UniServerModule.SessionManager.Sessions;
    try
      for I := 0 to ActiveSessions.SessionList.Count -1 do
      begin
        sid := ActiveSessions.SessionList[I];
        sid.AddJS('doShowText("Hello")');   // --- dont execute!?!
      end;
    finally
      SessionManager.Sessions.Unlock;
    end;
    AResponseInfo.ResponseNo := 200;
    AResponseInfo.ContentText := 'success';
    AResponseInfo.WriteContent;
    Handled := True;
  end;

end;

Hi

Why is this javascript function doShowText() in this active session not executing? It works if I call directly from UnimForm.UniSession.AddJS(), but not over the SessionManager...?

best regards