Message Box Pop-Up When Not Enough Values are Inputted VB.NET

Instead of getting an unhandled exception when there isn't enough values inputted (has to be over 500) I would like a message box to pop up to inform the user that not enough values were inputted. Here is what I tried:

Public Class Form1

Dim P_range0 As Double = 1.0672255
Dim P_range100 As Double = 0.9485795
Dim P_range200 As Double = 0.882981
Dim P_range300 As Double = 0.845339
Dim P_range400 As Double = 0.635712
Dim P_range500 As Double = 0.4302155

Dim M_range0 As Double = 0.8731845
Dim M_range100 As Double = 0.7761105
Dim M_range200 As Double = 0.722439
Dim M_range300 As Double = 0.691641
Dim M_range400 As Double = 0.520128
Dim M_range500 As Double = 0.3519945

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim var As String
    var = TextBox1.Text
    Dim numbers() As Double = var.Split(","c).Select(Function(s) Val(s)).ToArray()

    If (var < numbers(500)) Then
        MessageBox.Show("Not enough values inputted")
        If (M_range0 <= numbers(0)) AndAlso (numbers(0) <= P_range0) Then
            If (M_range100 <= numbers(99)) AndAlso (numbers(99) <= P_range100) Then
                If (M_range200 <= numbers(199)) AndAlso (numbers(199) <= P_range200) Then
                    If (M_range300 <= numbers(299)) AndAlso (numbers(299) <= P_range300) Then
                        If (M_range400 <= numbers(399)) AndAlso (numbers(399) <= P_range400) Then
                            If (M_range500 <= numbers(499)) AndAlso (numbers(499) <= P_range500) Then
                                MessageBox.Show("Test Passed")
                            Else
                                MessageBox.Show("Test Failed")
                            End If
                        Else
                            MessageBox.Show("Test Failed")
                        End If
                    Else
                        MessageBox.Show("Test Failed")
                    End If
                Else
                    MessageBox.Show("Test Failed")
                End If
            Else
                MessageBox.Show("Test Failed")
            End If
        Else
            MessageBox.Show("Test Failed")
        End If
    End If


End Sub

Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged

End Sub

End Class