Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click

        Dim firstNumber As Single = 0
        Dim secondNumber As Single = 0
        Dim totalDue As Single = 0

        firstNumber = CSng(txt1.Text)
        secondNumber = CSng(txt2.Text)
        totalDue = firstNumber + secondNumber
        Label1.Text = DoFormat(totalDue)

    End Sub

    Private Function DoFormat(ByVal x As Single) As String

        '---this function accepts a Single number type and returns a formatted string
        Dim myResult As String = ""

        '---make 2 decimal places and show $
        myResult = FormatCurrency(x, 2)
        Return myResult       'now send back the formatted string to the btnAdd_Click event so it can be shown in the label.

    End Function