'    Project:   Simple Calculation
' Programmer:   Andy McCone
'       Date:   Oct 5th 2007
'Description:   This project multiplies Price * Quantity
'               Returns the Subtotal, Tax and Total

Public Class mainForm
   Dim m_runningTotalDecimal As Decimal
   Dim m_numberOfSalesInteger As Integer
   Const m_TAX_RATE_decimal As Decimal = 0.089D

   Private Sub calculateButton_Click(ByVal sender As Object, ByVal e
As System.EventArgs) Handles calculateButton.Click
       Dim priceDecimal As Decimal
       Dim quantityInteger As Integer
       Dim subtotalDecimal As Decimal
       Dim taxDecimal, totalDecimal As Decimal

       Try
           If IsNumeric(priceTextbox.Text) Then
               If IsNumeric(quantityTextbox.Text) Then
                   If nameTextBox.Text <> "" Then

                       'Capture numbers from textboxes and put into variables
                       quantityInteger = CInt(quantityTextbox.Text)
                       priceDecimal = CDec(priceTextbox.Text)

                       'Calculate price*quantity, the tax and the total
                       subtotalDecimal = priceDecimal * quantityInteger
                       taxDecimal = subtotalDecimal * m_TAX_RATE_decimal
                       totalDecimal = subtotalDecimal + taxDecimal

                       'Add to Running Total and Number of sales
                       m_runningTotalDecimal += totalDecimal
                       m_numberOfSalesInteger += 1

                       'Display results in labels
                       subtotalLabel.Text = FormatCurrency(subtotalDecimal)
                       taxLabel.Text = FormatCurrency(taxDecimal)
                       totalLabel.Text = FormatCurrency(totalDecimal)
                   Else
                       MessageBox.Show("Please fill out your Name", "Erorr")
                   End If
               Else
                   MessageBox.Show("Use number only for the quantity", "Erorr")
               End If
           Else
               MessageBox.Show("Use numbers only for the price", "Error")
           End If

       Catch ex As Exception

           MessageBox.Show("Internal program error, we are very
sorry.", "Error Message", MessageBoxButtons.OK,
MessageBoxIcon.Warning)
           priceTextbox.Text = ""

       End Try

   End Sub

   Private Sub summaryButton_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles summaryButton.Click

       'Display Running Total and Number of sales
       runningTotalLabel.Text = FormatCurrency(m_runningTotalDecimal)
       numOfSalesLabel.Text = FormatNumber(m_numberOfSalesInteger)

   End Sub
End Class