...

Public Class Form1
'Timer Code
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        If GetAsyncKeyState(121)
            MsgBox("Test")
        End If
    End Sub
'Module Code
Module Module1
    Public Declare Function GetAsyncKeyState Lib "user32" Alias "GetAsyncKeyState" (ByVal vKey As Long) As Integer
End Module