public class Client{

  public static void Main(){

    BankAccount ba = new BankAccount("Peter");

    if (ba.AccountOK && ba.EnoughMoney(1000))
      ba.WithDraw(1000);
    else
      WithdrawingProblems("...");
    if (!ba.AccountOK)
      MajorProblem("...");
    if (ba.Balance <= 0)
      BankAccountOverdrawn(ba);

    ...
  
    if (ba.AccountOK)
      ba.Deposit(1500);
    if (!ba.AccountOK)
      MajorProblem("...");

  }
}