I cant calculate the correct numbers via select case - vb.net

Question

Im trying to get the discounted price using select case but i keep getting the regular price
I select student and click on yoga and personal trainer option then i put 11 months according to the calculation its supppose to be 76.50 monthly fee , total 841.50 but i get 85 monthly and total 935 . Help Thank you
Protected Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click
Dim decMontlyFee As Decimal
Dim decTotalFee As Decimal
Dim discount As Double
Dim intMonths As Integer
Dim decAdultFee As Decimal = 40
Dim decChildFee As Decimal = 20
Dim decStudentFee As Decimal = 25
Dim decSeniorFee As Decimal = 30
Dim decYogaFee As Decimal = 10
Dim decKarateFee As Decimal = 30
Dim decTrainerFee As Decimal = 50
If radAdult.Checked = True Then
decMontlyFee = decAdultFee
ElseIf radChild.Checked = True Then
decMontlyFee = decChildFee
ElseIf radStudent.Checked = True Then
decMontlyFee = decStudentFee
ElseIf radSenior.Checked = True Then
decMontlyFee = decSeniorFee
End If
If chkYoga.Checked = True Then
decMontlyFee += decYogaFee
End If
If chkTrainer.Checked = True Then
decMontlyFee += decTrainerFee
End If
If chkKarate.Checked = True Then
decMontlyFee += decKarateFee
End If
Select Case intMonths
Case Is <= 3
discount = 0
Case 4 To 6
discount = decMontlyFee * 0.05
Case 7 To 9
discount = decMontlyFee * 0.08
Case Is >= 10
discount = decMontlyFee * 0.1
End Select
decMontlyFee -= discount
decTotalFee = decMontlyFee * txtMonths.Text
lblMonthlyFee.Text = decMontlyFee.ToString("c")
lblTotalFee.Text = decTotalFee.ToString("c")
End Sub
End Class

Answer 1

You will need to read the value for intMonths because it is only declared and not assigned.

Answer 2

Assign your intMonths to the TextBox value. Simplify your syntax.
Protected Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click
Dim decMontlyFee As Decimal
Dim decTotalFee As Decimal
Dim intMonths As Integer = Integer.Parse(txtMonths.Text)
Dim decAdultFee As Decimal = 40
Dim decChildFee As Decimal = 20
Dim decStudentFee As Decimal = 25
Dim decSeniorFee As Decimal = 30
Dim decYogaFee As Decimal = 10
Dim decKarateFee As Decimal = 30
Dim decTrainerFee As Decimal = 50
decMontlyFee = If(radAdult.Checked, decAdultFee, decMontlyFee)
decMontlyFee = If(radChild.Checked, decChildFee, decMontlyFee)
decMontlyFee = If(radStudent.Checked, decStudentFee, decMontlyFee)
decMontlyFee = If(radSenior.Checked, decSeniorFee, decMontlyFee)
decMontlyFee += If(chkYoga.Checked, decYogaFee, 0)
decMontlyFee += If(chkTrainer.Checked, decTrainerFee, 0)
decMontlyFee += If(chkKarate.Checked, decKarateFee, 0)
Select Case intMonths
Case Is <= 3
decMontlyFee *= 1
Case 4 To 6
decMontlyFee *= 0.95
Case 7 To 9
decMontlyFee *= 0.92
Case Is >= 10
decMontlyFee *= 0.9
End Select
decTotalFee = decMontlyFee * intMonths
lblMonthlyFee.Text = decMontlyFee.ToString("c")
lblTotalFee.Text = decTotalFee.ToString("c")
End Sub