Question Hotkeys in other process

[Humpasaur]

I'm trying to make it when I press the "down" key in a certain process(ex. Firefox), it opens the msgbox. Right now it only works when I press it with the form open...

    Private Sub client_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown
        If e.KeyCode = Keys.Down Then
            MsgBox("You pressed it")
        End If
    End Sub

Thanks guys