I messed up somewhere with my variables and now when I do any data validation the program crashes and will not catch the error, The number of passengers has to be a number between 1 and 10 here is my code



Option Strict On
Public Class Form1

Private Sub DepartKenaiRadioButton_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles DepartKenaiRadioButton.CheckedChanged
'disable and enable radio buttons
If DepartKenaiRadioButton.Checked = True Then
DestKenaiRadioButton.Enabled = False
DestSewardRadioButton.Enabled = True
DestHomerRadioButton.Enabled = True
DestNinilchikRadioButton.Enabled = True
End If
End Sub

Private Sub DepartSewardRadioButton_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles DepartSewardRadioButton.CheckedChanged
'disable and enable radio buttons
If DepartSewardRadioButton.Checked = True Then
DestSewardRadioButton.Enabled = False
DestKenaiRadioButton.Enabled = True
DestHomerRadioButton.Enabled = True
DestNinilchikRadioButton.Enabled = True
End If
End Sub

Private Sub DepartHomerRadioButton_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles DepartHomerRadioButton.CheckedChanged
'disable and enable radio buttons
If DepartHomerRadioButton.Checked = True Then
DestHomerRadioButton.Enabled = False
DestKenaiRadioButton.Enabled = True
DestSewardRadioButton.Enabled = True
DestNinilchikRadioButton.Enabled = True
End If
End Sub

Private Sub DepartNinilchikRadioButton_CheckedChanged(sender As System.Object, e As System.EventArgs) Handles DepartNinilchikRadioButton.CheckedChanged
'disable and enable radio buttons
If DepartNinilchikRadioButton.Checked = True Then
DestNinilchikRadioButton.Enabled = False
DestKenaiRadioButton.Enabled = True
DestSewardRadioButton.Enabled = True
DestHomerRadioButton.Enabled = True
End If
End Sub

Private Sub QuoteButton_Click(sender As System.Object, e As System.EventArgs) Handles QuoteButton.Click
'declare variables
Dim NumPassengersInteger As Integer
Dim QuotePassengerCostDecimal As Decimal
Dim PlaneTypeString As String
Dim TicketCostDecimal As Decimal

'Declare constants
Const ONE_KENAI_TO_SEWARD_DECIMAL As Decimal = 180
Const ONE_KENAI_TO_NINILCHIK_DECIMAL As Decimal = 150
Const ONE_KENAI_TO_HOMER_DECIMAL As Decimal = 200
Const ONE_SEWARD_TO_NINILCHIK_DECIMAL As Decimal = 225
Const ONE_SEWARD_TO_HOMER_DECIMAL As Decimal = 190
Const ONE_NINILCHIK_TO_HOMER_DECIMAL As Decimal = 170
Const ROUND_KENAI_TO_SEWARD_DECIMAL As Decimal = 300
Const ROUND_KENAI_TO_NINILCHIK_DECIMAL As Decimal = 250
Const ROUND_KENAI_TO_HOMER_DECIMAL As Decimal = 335
Const ROUND_SEWARD_TO_NINILCHIK_DECIMAL As Decimal = 375
Const ROUND_SEWARD_TO_HOMER_DECIMAL As Decimal = 315
Const ROUND_NINILCHIK_TO_HOMER_DECIMAL As Decimal = 285

''Validation
'Try

'get num passengers
NumPassengersInteger = Integer.Parse(NumPassengersTextBox.Text)

'Get plane type
If NumPassengersInteger = 1 Then
PlaneTypeString = "Piper Cub"
End If

If NumPassengersInteger = 2 Or NumPassengersInteger = 3 Then
PlaneTypeString = "Cessna 170"
End If

If NumPassengersInteger = 4 Or NumPassengersInteger = 5 Then
PlaneTypeString = "Cessna 206"
End If

If NumPassengersInteger > 5 Or NumPassengersInteger < 11 Then
PlaneTypeString = "DeHavilland Beaver"
End If

AircraftTextBox.Text = PlaneTypeString


'find ticket cost
If DepartKenaiRadioButton.Checked = True And DestSewardRadioButton.Checked = True Then
TicketCostDecimal = ONE_KENAI_TO_SEWARD_DECIMAL
End If

If DepartKenaiRadioButton.Checked = True And DestNinilchikRadioButton.Checked = True Then
TicketCostDecimal = ONE_KENAI_TO_NINILCHIK_DECIMAL
End If

If DepartKenaiRadioButton.Checked = True And DestHomerRadioButton.Checked = True Then
TicketCostDecimal = ONE_KENAI_TO_HOMER_DECIMAL
End If

If DepartSewardRadioButton.Checked = True And DestNinilchikRadioButton.Checked = True Then
TicketCostDecimal = ONE_SEWARD_TO_NINILCHIK_DECIMAL
End If

If DepartSewardRadioButton.Checked = True And DestHomerRadioButton.Checked = True Then
TicketCostDecimal = ONE_SEWARD_TO_HOMER_DECIMAL
End If

If DepartNinilchikRadioButton.Checked = True And DestHomerRadioButton.Checked = True Then
TicketCostDecimal = ONE_NINILCHIK_TO_HOMER_DECIMAL
End If

If DepartKenaiRadioButton.Checked = True And DestSewardRadioButton.Checked = True And RoundTripCheckBox.Checked = True Then
TicketCostDecimal = ROUND_KENAI_TO_SEWARD_DECIMAL
End If

If DepartKenaiRadioButton.Checked = True And DestNinilchikRadioButton.Checked = True And RoundTripCheckBox.Checked = True Then
TicketCostDecimal = ROUND_KENAI_TO_NINILCHIK_DECIMAL
End If

If DepartKenaiRadioButton.Checked = True And DestHomerRadioButton.Checked = True And RoundTripCheckBox.Checked = True Then
TicketCostDecimal = ROUND_KENAI_TO_HOMER_DECIMAL
End If

If DepartSewardRadioButton.Checked = True And DestNinilchikRadioButton.Checked = True And RoundTripCheckBox.Checked = True Then
TicketCostDecimal = ROUND_SEWARD_TO_NINILCHIK_DECIMAL
End If

If DepartSewardRadioButton.Checked = True And DestHomerRadioButton.Checked = True And RoundTripCheckBox.Checked = True Then
TicketCostDecimal = ROUND_SEWARD_TO_HOMER_DECIMAL
End If

If DepartNinilchikRadioButton.Checked = True And DestHomerRadioButton.Checked = True And RoundTripCheckBox.Checked = True Then
TicketCostDecimal = ROUND_NINILCHIK_TO_HOMER_DECIMAL
End If

'determind quote
QuotePassengerCostDecimal = NumPassengersInteger * TicketCostDecimal
RateTextBox.Text = CStr(QuotePassengerCostDecimal)

'Catch FormatNumPassengerException As FormatException
' MessageBox.Show("Please enter Number of passengers as a positive number format", "Error", MessageBoxButtons.OK)
'End Try

End Sub

Private Sub ClearButton_Click(sender As System.Object, e As System.EventArgs) Handles ClearButton.Click
'reset to defaults
DepartKenaiRadioButton.Enabled = True
DepartKenaiRadioButton.Checked = True

DestHomerRadioButton.Checked = False
DestKenaiRadioButton.Checked = False
DestNinilchikRadioButton.Checked = False
DestSewardRadioButton.Checked = False
RoundTripCheckBox.Checked = False
NumPassengersTextBox.Clear()
AircraftTextBox.Clear()
RateTextBox.Clear()

'focus to depart group box
DepartGroupBox.Focus()

End Sub

Private Sub CloseButton_Click(sender As System.Object, e As System.EventArgs) Handles CloseButton.Click
Me.Close()
End Sub
End Class