public static void main(String[] args) {
        String use = "";
        LookAndFeelInfo[] available = UIManager.getInstalledLookAndFeels();
        for(LookAndFeelInfo info : available) {
            if(info.toString().contains("Nimbus")) {
                use = info.toString();
            }
        }
        try {
            UIManager.setLookAndFeel(use);
        }
        catch (ClassNotFoundException ex) {}
        catch (InstantiationException ex) {}
        catch (IllegalAccessException ex) {} 
        catch (UnsupportedLookAndFeelException ex) {}
        //new LoginScreen();
        new MainGUI(new User(1));
    }