iii. the net sales amount.

Public Class MainForm

Private Function ComputeDiscount$($ByVal quantity As Integer$)$ As Double

Dim discount As Double

If quantity $101$ Then

discount $=0\mathrm{.}10$

Elself quantity $26$ Then

discount $=0\mathrm{.}08$

Elself quantity $11$ Then

discount $=0\mathrm{.}05$

Else

discount $=0$

End If

Return discount

End Function

Private Sub ComputeSalesButton$\_$Click$($sender As Object, e As EventArgs$)$ Handles ComputeSalesButton.Click

Dim price As Double

Dim quantity As Integer

Dim grossSales As Double

Dim discount As Double

Dim netSales As Double

$\text{'}$ Parse input values

If Double.TryParse$($ItemPriceTextBox$.$Text, price$)$ AndAlso Integer.TryParse$($QuantitySoldTextBox$.$Text, quantity$)$ Then

$\text{'}$ Compute gross sales

grossSales $=$ price $*$ quantity

$\text{'}$ Compute discount

discount $=$ ComputeDiscount $($quantity$)$

$\text{'}$ Compute net sales

netSales $=$ grossSales $*$ discount