This can also be done simple.
You can use either If Else or Switch case method..
You can do on "button click" event...
Place a Listbox1 and Button1 controls on Form1.vb[Design]
and type the following code in Form1.vb
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If (ListBox1.SelectedIndex = 0) Then
Form2.Show()
ElseIf (ListBox1.SelectedIndex = 1) Then
Form3.Show()
End If
End Sub