Private Sub ToolStripMenuItem1_Click(sender As System.Object, e As System.EventArgs) Handles ToolStripMenuItem1.Click, ToolStripMenuItem2.Click
        Dim ToolStripItem As ToolStripItem = DirectCast(sender, ToolStripItem)
        Dim ContextMenuStrip As ContextMenuStrip = ToolStripItem.Owner
        Select Case ToolStripItem.Name
            Case "ToolStripMenuItem1"
                Incolla(ContextMenuStrip.SourceControl)
            Case "ToolStripMenuItem2"
                Taglia(ContextMenuStrip.SourceControl)
        End Select

    End Sub

    Sub Copia(ByVal RichTextBox As RichTextBox)
        '...
    End Sub

    Sub Taglia(ByVal RichTextBox As RichTextBox)
        '...
    End Sub

    Sub Incolla(ByVal RichTextBox As RichTextBox)
       RichTextBox.Text = Clipboard.GetText()
    End Sub