How to create Yes / No?

So this code allows the users to save their object, created in the main. However I wish to create a function (if statement i think) which will ask the users whether they wish to save it (results.txt). If they do then save, if not then exit the program. Thanks.

    import java.io.FileOutputStream;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;

    public class Main {

    public static void main( String args[] ) //Standard header for main method
        {
    Person arthur = new Person();
    arthur.name = "Arthur Dent";
    arthur.age= 21;



    System.out.println("\nDo you wish to save these results? (Y / N)");


    String fileName = "results.txt";
    try {

    ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream(fileName));
    os.writeObject(arthur); //write object
    os.close();


    } catch (IOException e) {
    e.printStackTrace();
    }

    System.out.println("\nYour results are saved!");

    }
    }