Public Class CaseStudyCh3_Auto_Center

    'Declares commission rate @ 20%.
    Const CommissionRateDecimal As Decimal = 0.2D

    Private Sub CalculateButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CalculateButton.Click

        'Declares variables used in calculation; Sales price, cost price, commission, and MessageString.
        Dim MessageString As String
        Dim SalesPriceDecimal, CostPriceDecimal, CommissionDecimal As Decimal


        'Confirms employee's name is entered and parses sales price and cost price into their decimal variables.
        If EmployeeNameTextBox.Text <> String.Empty Then
            Try
                SalesPriceDecimal = Decimal.Parse(SalesPriceTextBox.Text)
            Catch SalesPriceException As FormatException
                'Catches sales price exception if input is not formatted as a decimal value.
                MessageString = "Please enter sales price as a decimal with no dollar signs."
                MessageBox.Show(MessageString, "Error, Will Robinson!",
                                MessageBoxButtons.OK)
                With SalesPriceTextBox
                    .Focus()
                    .SelectAll()
                End With
            End Try

            Try
                CostPriceDecimal = Decimal.Parse(CostPriceTextBox.Text)
            Catch CostPriceException As FormatException
                'Catches cost price exception if input is not formatted as a decimal.
                MessageString = "Please enter cost price as a decimal with no dollar signs."
                MessageBox.Show(MessageString, "Error, Will Robinson!", MessageBoxButtons.OK)
                With CostPriceTextBox
                    .Focus()
                    .SelectAll()
                End With
            End Try
        Else
            'Displays error if employee's name is omitted.
            MessageString = "Please enter employee's name."
            MessageBox.Show(MessageString, "Error, Will Robinson!", MessageBoxButtons.OK)
            With EmployeeNameTextBox
                .Focus()
                .SelectAll()
            End With
        End If

        'Calculates commission for employee.
        If SalesPriceDecimal > CostPriceDecimal Then
            CommissionDecimal = CommissionRateDecimal * (SalesPriceDecimal - CostPriceDecimal)
        Else
            CommissionDecimal = 0
        End If

        'Displays commission total in text field.
        CommissionTextBox.Text = CommissionDecimal.ToString("C")

    End Sub

    Private Sub ClearButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ClearButton.Click

        'Clears all fields for new entry.
        With EmployeeNameTextBox
            .Clear()
            .Focus()
        End With
        SalesPriceTextBox.Clear()
        CostPriceTextBox.Clear()
        CommissionTextBox.Clear()

    End Sub

    Private Sub PrintButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PrintButton.Click

        'Prints the form; need that $$$BLINGBLING$$$!
        PrintForm1.PrintAction = Printing.PrintAction.PrintToPreview
        PrintForm1.Print()

    End Sub

    Private Sub ExitButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitButton.Click

        'Closes the program.
        Me.Close()

    End Sub
End Class