// in Account.java

public class Account {
    private int balance;

    public Account() {
	balance = 0;	// initialize balance to zero
    }

    // use synchronized to prohibit concurrent access of balance
    public synchronized void Deposit(int deposit) {
        int newbalance; // local variable

        newbalance = balance + deposit;
        balance = newbalance;
    }

    public synchronized int GetBalance() {
	return balance;	  // return current balance
    }
}