Public Class Form1
Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseDown
        Select Case e.Button
            Case Is = Windows.Forms.MouseButtons.Right
                Label1.Text = "Hai premuto il tasto destro"
            Case Is = Windows.Forms.MouseButtons.Left
                Label1.Text = "Hai premuto il tasto sinistro"
            Case Is = Windows.Forms.MouseButtons.Middle
                Label1.Text = "Hai premuto il tasto centrale"
        End Select
    End Sub
End Class [/Code]