creditsystem Credit.java

public class Credit
{
    static private double balance;
    private double adjustment;

    public Credit()
    {   System.out.println("Credit default constructor");   }

    public static void increaseCredit( double adjustment )
    {   balance += adjustment;
    }

    public static void decreaseCredit( double adjustment )
    {   balance -= adjustment;
    }

    public static double getCreditBalance()
    {   return balance;
    }
} //end class