buttons

boolean startMenu = true;
boolean stopStart = false;//true - everything is working , false - everything is stoped

void setup() {
cp5 = new ControlP5(this);

  //creating buttons

  cp5.addButton("Menu").setPosition(pozX, 2).setSize(button_width, button_height);
  cp5.addButton("Start").setPosition(centerX, centerY).setSize(200, 60).setCaptionLabel("Start Programu").hide();
  cp5.addButton("Settings").setPosition(centerX, centerY+ 60).setSize(200, 60).setCaptionLabel("Ustawienia").hide();
  cp5.addButton("Save").setPosition(pozXSet, 63).setSize(button_width, button_height).setCaptionLabel("Zapis").hide();
  cp5.addButton("Load").setPosition(pozXSet, 63).setSize(button_width, button_height).setCaptionLabel("Odczyt").hide();
  cp5.addButton("Set").setPosition(pozXSet, 63).setSize(button_width, button_height).setCaptionLabel("Ustawienia").hide();
  cp5.addButton("Exit").setPosition(centerX, centerY + 120).setSize(200, 60).setCaptionLabel("Wyjscie z programu").hide();
  cp5.addButton("Reset").setPosition(pozX, he * hi).setSize(button_width, button_height);
}

void Start() {

  stopStart = true;
  startMenu = false;

  cp5.get(Button.class, "Start").hide();
  cp5.get(Button.class, "Settings").hide();
  cp5.get(Button.class, "Exit").hide();
}

void Settings() {
}

void Exit() {
  exit();
}

void menuManagement()
{
  if(startMenu)
  {
  cp5.get(Button.class, "Start").show();
  cp5.get(Button.class, "Settings").show();
  cp5.get(Button.class, "Exit").show();
  } else if (startMenu == false)
  {
  cp5.get(Button.class, "Start").hide();
  cp5.get(Button.class, "Settings").hide();
  cp5.get(Button.class, "Exit").hide();
  }
}