Setting up menu
// First, create a menu
mnFile = new Menu("File");
miFile = new MenuItem[3];
// then, create items
miFile[0] = new MenuItem("Open");
miFile[0].setOnAction(this);
miFile[1] = new MenuItem("Edit");
miFile[1].setOnAction(this);
miFile[2] = new MenuItem("Finish");
miFile[2].setOnAction(this);
// Then, add the items to the menu
mnFile.getItems().addAll(miFile);
menuBar = new MenuBar();
menuBar.getMenus().addAll(mnFile);