VB 10, need help

Trying to make my first program in VB 10, a calculator to determine how much one should study a day.

It says: Object variable or With block variable not set.
in rule: If Asc(e.KeyChar) <> 8 Then

Code:

Public Class Form1
    Dim N
    Dim message1 = "You have to study "
    Dim message2 = " hours a day."
    Dim message3 = " hour a day."
    Dim messagex
    Dim messageErrorInteger = "Please enter a number between 1 and 50"
    Dim time
    Dim hours
    Dim days
    Dim Stime = 40
    Dim e = TextBox1 'as integer??
    Dim s = TextBox1
    Public Sub Calculate_N()
        N = (Stime) - (((time / (60)) * hours) / (days))
    End Sub
    Public Sub Calculate() Handles Button1.Click



        '97 - 122 = Ascii codes for simple letters
        '65 - 90  = Ascii codes for capital letters
        '48 - 57  = Ascii codes for numbers

        If Asc(e.KeyChar) <> 8 Then
            If Asc(e.KeyChar) < 48 Or Asc(e.KeyChar) > 57 Then
                e.Handled = True
            Else : e.Handled = False
            End If
            If e.Handled = False Then MsgBox(messageErrorInteger)
        End If

        If e < 51 And e > 0 Then s.Handled = True Else s.Handled = False
        If s.Handled = True Then s.Handled = hours


        If N = 1 Then messagex = message3 Else messagex = message2
        MsgBox(message1 & N & messagex)

    End Sub
End Class

what language is this?

I am a duck!

QUACK QUACK

install gentoo

>2013
>programming the electric Jew