Sales report

[burntout]

I am doing a sales report for a clothing manufacturer that calculates its total sales for the week.Sales values are inputed seperatly for each clothing item, but the amount of sales for each of the five weekdays should be inputed all at once.The app should calculate the total amount of sales for each item in the week and also the total sales for the manufacturer for all the items in the week. The manufacturer is a small company so it produces at most 10 items in any week. This is what i have so far:

Public Class SalesReportForm

   Dim itemCount As Integer = 0 'stores the number of items added
   Dim itemNames(0 To 9) As String
   'Declare two dimensional decimal array
   Dim itemSales As Decimal(,) = New Decimal(9, 4) {}

   ' Display the sales report
   Sub DisplaySales()

      ' clear the ListBox
      outputListBox.Items.Clear()

      ' create a header for the ListBox
      outputListBox.Items.Add("Name" & ControlChars.Tab & _
         ControlChars.Tab & "Mon." & ControlChars.Tab & "Tue." & _
         ControlChars.Tab & "Wed." & ControlChars.Tab & "Thu." & _
         ControlChars.Tab & "Fri." & ControlChars.Tab & "Total")

      Dim output As String
      Dim counterItem As Integer
      Dim counterDay As Integer
      Dim weekTotal As Decimal = 0 ' weekly sales total
      Dim salesTotal As Decimal = 0 ' total sales

    End Sub ' DisplaySales

    Private Sub submitButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles submitButton.Click
    Dim item As String

    item = itemNames(itemCount) 'assign item name to itemnames array indexed with itemcount
' assign dailysales to two dimensional itemsales array
    itemSales(itemCount, 0) = Convert.ToDecimal(mondayTextBox.Text)
    itemSales(itemCount, 1) = Convert.ToDecimal(tuesdayTextBox.Text)
    itemSales(itemCount, 2) = Convert.ToDecimal(wednesdayTextBox.Text)
    itemSales(itemCount, 3) = Convert.ToDecimal(thursdayTextBox.Text)
    itemSales(itemCount, 4) = Convert.ToDecimal(fridayTextBox.Text)

 'increment  variable itemCount to record another sales data being added
    If itemSales = True Then
        itemCount += 1
    End If

My problem right now is the last line of code, I need to 'increment variable itemCount to record another sales data being added. I started with itemsales or items in my if statment but im not sure if this is right. Im a bit confused with this part. Should i continue with this statment or try another like a select case?