Inheritance

[lbgladson]

I have the following classes for a bank account. I am hoping someone can point me to where the problems in my code are. When I run the program my output is:

account1
Inheritance_Part1.SavingsAccount
Interest rate: 0.00%
Interest earned: $25.00
Balance: $25.00

account2
Inheritance_Part1.CheckingAccount
Transaction fee: $1.00
Balance: $80.00

Attempting to debit account1 by $20.00
Interest rate: 0.00%
Interest earned: $20.00
Balance: $20.00

Attempting to debit account2 by $40.00
Transaction fee: $1.00
Balance: $40.00

Crediting $40.00 to account1
Interest rate: 0.00%
Interest earned: $20.00
Balance: $20.00

Crediting $65.00 to account2
Transaction fee: $1.00
Balance: $40.00

When it should say...

account1
Inheritance_Part1.SavingsAccount
Interest rate: 3.00%
Interest earned: $0.06
Balance: $25.06

account2
Inheritance_Part1.CheckingAccount
Transaction fee: $1.00
Balance: $80.00

Attempting to debit account1 by $20.00
Interest rate: 3.00%
Interest earned: $0.01
Balance: $5.08

Attempting to debit account2 by $40.00
Transaction fee: $1.00
Balance: $39.00

Crediting $40.00 to account1
Interest rate: 3.00%
Interest earned: $0.11
Balance: $45.19

Crediting $65.00 to account2
Transaction fee: $1.00
Balance: $103.00

Here are the codes:

Public Class Account
    Private balanceValue As Decimal

    Public Sub New(ByVal balance As Decimal)
        balanceValue = balance
    End Sub

    Public Property Balance() As Decimal
        Get
            Return balanceValue
        End Get
        Set(ByVal value As Decimal)
            If value >= 0.0 Then
                balanceValue = value
            Else
                balanceValue = CDec(0.0)
            End If
        End Set
    End Property

    Overridable Sub Credit(ByVal value As Decimal)
        value = balanceValue + value
    End Sub
    Public Overridable Function Debit(ByVal value As Decimal) As Boolean
        If value > balanceValue Then
            value = CDec(False)
        ElseIf value <= balanceValue Then
            balanceValue = value
            value = CDec(True)
        End If
        Return CBool(value)
    End Function

    Public Overrides Function ToString() As String
        Return (String.Format("Balance: {0:C2}", Balance) & vbCrLf)
    End Function
End Class

Public Class SavingsAccount
    Inherits Account

    Dim interestRate As Double

    Public Sub New(ByVal balance As Decimal, ByVal rate As Double)
        MyBase.New(balance)
        rate = interestRate
    End Sub

    Public Property Rate() As Double
        Get
            Return interestRate
        End Get

        Set(ByVal value As Double)
            If value >= 0.0 Then
                interestRate = Rate
            Else
                interestRate = 0.0
            End If
        End Set
    End Property

    Public Function CalculateInterest() As Decimal
        Dim interest As Decimal
        interest = CDec(Balance * interestRate / 12)
        interest = interest + Balance
        Return interest
    End Function

    Public Overrides Function ToString() As String
        Dim message As String
        message = String.Format("Interest rate: {0:p2}", Rate) & vbCrLf
        message &= String.Format("Interest earned: {0:c2}", CalculateInterest()) & vbCrLf
        message &= MyBase.ToString()
        Return message
    End Function
End Class

Public Class CheckingAccount
    Inherits Account

    Private transactionFee As Decimal

    Public Sub New(ByVal balance As Decimal, ByVal transaction As Decimal)
        MyBase.New(balance)
        Fee = transaction
    End Sub

    Public Property Fee() As Decimal
        Get
            Return transactionFee
        End Get
        Set(ByVal value As Decimal)
            If value >= 0.0 Then
                transactionFee = value
            Else
                transactionFee = CDec(0.0)
            End If
        End Set
    End Property

    Public Overrides Sub Credit(ByVal value As Decimal)
        MyBase.Credit(value)
        value = Balance - transactionFee
    End Sub

    Public Overrides Function Debit(ByVal value As Decimal) As Boolean
        Return MyBase.Debit(value)
        If True Then
            value = Balance - transactionFee
            Return True
        Else
            Return False
        End If
    End Function

    Public Overrides Function ToString() As String
        Dim message As String
        message = String.Format("Transaction fee: {0:C2}", Fee) & vbCrLf
        message &= MyBase.ToString()
        Return message
    End Function
End Class

Public Class AccountTesterForm

    Private Sub AccountTesterForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim account1 As New SavingsAccount(25, 0.03)
        Dim account2 As New CheckingAccount(80, 1)

        ' display initial balance of each object
        balanceLabel.Text = "account1" & vbCrLf & Convert.ToString(account1.GetType()) & vbCrLf & account1.ToString() & vbCrLf
        balanceLabel.Text &= "account2" & vbCrLf & Convert.ToString(account2.GetType()) & vbCrLf & account2.ToString() & vbCrLf
        ' debit each account and show new balance

        balanceLabel.Text &= "Attempting to debit account1 by $20.00." & vbCrLf
        If account1.Debit(20) = True Then
            balanceLabel.Text &= account1.ToString() & vbCrLf
        End If

        balanceLabel.Text &= "Attempting to debit account2 by $40.00." & vbCrLf
        If account2.Debit(40) Then
            balanceLabel.Text &= account2.ToString() & vbCrLf
        End If

        ' credit each account and show new balance
        balanceLabel.Text &= "Crediting $40.00 to account1." & vbCrLf
        account1.Credit(40)
        balanceLabel.Text &= account1.ToString() & vbCrLf

        balanceLabel.Text &= "Crediting $65.00 to account2." & vbCrLf
        account2.Credit(65)
        balanceLabel.Text &= account2.ToString()


    End Sub
End Class