/**
 * A cash register totals up sales and computers change due.
 */
public class CashRegister
{
public CashRegister()
{
   purchase = 0;
   payment = 0;
}

public void recordPurchase(double amount)
{
    purchase = purchase + amount;
}

public static void main(String args[])
{
}
public void enterDollars(int dollars)
    {
        payment = payment + dollars;
    }
public void enterQuarters(int quarters)
    {
        payment = payment + quarters *QUARTER_VALUE;
    }

public double giveChange()
    {
        double change = payment - purchase;
        purchase = 0;
        payment = 0;
        return change;
    }

public static final double QUARTER_VALUE = 0.25;
public static final double DIME_VALUE = 0.1;
public static final double NICKLE_VALUE = 0.05;
public static final double PENNY_VALUE = 0.01;

private double purchase;
private double payment;
}