My variable doesn't work properly

Basically i've been trying to make something to create something since i got vb.net yesterday but i can't get this bit to work.

Public Class Main
Inherits System.Windows.Forms.Form
Dim var As String
Dim ability As String
Dim var2 As String
Dim About As New About

Private Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
var = "00"
ability = "00"
var2 = "00"
End Sub

Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
If ComboBox1.ValueMember = "1" Then var = "70" And var2 = "FA"
If ComboBox1.ValueMember = "2" Then var = "71" And var2 = "00"

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If var = "00" Then GoTo 2
TextBox1.Text = "somet" & vbCrLf & "somet" & var & ability & var2 & vbCrLf & "more somet" & vbCrLf & "even more somet"
Exit Sub
2: MsgBox("Select an option")
End Sub

Any help would be nice