Public Class MortgageCalculatorForm

   Private Sub calculateButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles calculateButton.Click
      Dim years As Integer = 2            'repetition counter
      Dim mortgageAmount As Integer = 0   'house price
      Dim interest As Double = 0          'interest rate
      Dim monthlyPayment As Decimal = 0   'monthly payment
      Dim monthlyInterest As Double = 0   'monthly interest rate

      '  remove text displayed in ListBox
      paymentsListBox.Items.Clear()


      'add header to ListBox
      paymentsListBox.Items.Add("Mortgage Length (Years) & ControlChars.Tab & ControlChars.Tab & "Monthly Payment")

      'retrieve user input and assign values to their respective variables
      interest = Val(interestTextBox.Text) / 100
      monthlyPayment = Val(resultListBox.Text)

      'determine monthly interest rate
      monthlyInterest = interest / 12

      'loop six times
      Do While years <= 7
         'calculate payment perieod
         years = 5 * years

         'calculate monthly paryment
         monthlyPaymetn = Convert.ToDecimal(Pmt(monthlyInterest, years, mortgageAmount))

         'display payment amount
         paymentsListBox.Items.Add(months & ControlChars.Tab & ControlCharts.Tab 7 String.Format("{0:C}", monthlyPayment))

         years += 5  'increment counter
      Loop
   End Sub
End Class ' MortgageCalculatorForm