Public Class mailorderForm
    'Declare constants
    Dim Handling0_TO_10 As Decimal
    Dim Handling10_TO_100 As Decimal
    Dim Handling100_Plus As Decimal
    Dim ShippingChargeDecimal As Decimal
    Dim Sales_TAXDecimal As Decimal

    'Declare Module-Level variables
    Dim amountDueDecimal As Decimal
    Dim weightTotalDecimal As Decimal

    Private Sub nextItemButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles nextItemButton.Click
        'Declare local variables
        Dim amountDueDecimal As Decimal
        Dim quantityInteger As Integer

        Dim priceDecimal As Decimal

        If nameTextBox.Text = "" Or addressTextBox.Text = "" Or cityTextBox.Text = "" Or stateTextBox.Text = "" Then
            MessageBox.Show("The Name, Address, and State Fields cannot be blank.")
        End If
        If descriptionTextBox.Text = "" Or quantityTextBox.Text = "" Or weightTextBox.Text = "" And priceTextBox.Text = "" Then
            MessageBox.Show("The Description, Quantity, Weight or Price Fields cannot be blank.")

        End If

        Try
            'Convert 
            quantityInteger = Integer.Parse(quantityTextBox.Text)
            weightTotalDecimal = Decimal.Parse(weightTotalTextBox.Text)

            'Calculate
            amountDueDecimal = quantityInteger * priceDecimal + weightTotalDecimal

            'Accumulator
            weightTotalDecimal = 
            amountDueDecimal =

        Catch ex As Exception

Dim totalPrice As Double

'calculate a price for something

totalPrice = totalPrice + price

'accumulators just keep of track of how much of something
'has accumulated.  Mainstream uses for these are things
'like total prices and such.  The price of each purchase is
'added to the total every time.  The total is an
'accumulator.