This application will allow the user to enter the number of units

Public Class Form1
Public Class Form1
Inherits System.Windows.Forms.Form

' Software Sales.
' This application will allow the user to enter the number of units
' Sold for each package.
' This application should calculate and display the total of the software
' order in a message box.

' Package A retail for: $99
' Package B retail for: $199
' Package C retail for: $299

Const decPackageA As Decimal = 99
Const decPackageB As Decimal = 199
Const decPackageC As Decimal = 299



' 10 - 19 20% discount
' 20 - 49 30% discount
' 50 - 99 40% discount
' 100 or more 50% discount



Const decDiscount10to19 As Decimal = 0.2D ' 10 to 19 quantities
Const decDiscount20to49 As Decimal = 0.3D ' 20 to 40 quantities
Const decDiscount50to99 As Decimal = 0.4D ' 50 to 99 quantities
Const decDiscount100orMore As Decimal = 0.5D ' 100 to more quantities



' Package A retail for: $99
' Package B retail for: $199
' Package C retail for: $299

Const decPackageA As Integer = 99
Const decPackageB As Integer = 199
Const decPackageC As Integer = 299



' 10 - 19 20% discount
' 20 - 49 30% discount
' 50 - 99 40% discount
' 100 or more 50% discount

' The following class-level constatns are used to calculate discounts.

Const decDiscount10to19 As Decimal = 0.2D ' 10 to 19 quantities
Const decDiscount20to49 As Decimal = 0.3D ' 20 to 40 quantities
Const decDiscount50to99 As Decimal = 0.4D ' 50 to 99 quantities
Const decDiscount100orMore As Decimal = 0.5D ' 100 to more quantities


Dim decPackageA As Integer ' First unit sold
Dim decPackageB As Integer ' Second unit sold
Dim decPackageC As Integer ' Third unit sold
Dim intGrandTotal As Integer ' Grand Total
Dim decDiscount As Decimal ' Discount

decPackageA = CInt(decPackageA - decDiscount)
decPackageB = CInt(decPackageB - decDiscount)
decPackageC = CInt(decPackageC - decDiscount)
intGrandTotal = CInt(decPackageA + decPackageB + decPackageC * decDiscount)

' Check and make sure the number of units for each package is numeric
' and is not negative.
Try
decPackageA = CInt(txtPackageA.Text)
decPackageB = CInt(txtPackageB.Text)
decPackageC = CInt(txtPackageC.Text)

Catch ex As Exception
MessageBox.Show("Must be numeric, and not negative", _
"Input Error")
Return
End Try

' Check the quantity range: must be 1 or >.
If (decPackageA .
If (decPackageB .
If (decPackageC = 100
decDiscount = decPackageA * decDiscount100orMore
End Select

Select Case decPackageB
Case 10 To 19
decDiscount = decPackageB * decDiscount10to19
Case 20 To 49
decDiscount = decPackageB * decDiscount20to49
Case 50 To 99
decDiscount = decPackageB * decDiscount50to99
C