// methods
        public bool setUser(string login,string password) {
            this.currentUser = dbUsers.getUser(login,password);

            if(this.currentUser != null) {
                validUserLoggedInEventArgs args = new validUserLoggedInEventArgs(login);
                validUserLoggedIn(this,args);
                return true;
            }

            return false;
        }
 // app event handlers
 void app_validUserLoggedIn(object sender,validUserLoggedInEventArgs e) {
     fillMenu(app.currentUser.getMenuItems());
 }