Public Class Form1
#Region " declarations "
Dim strUndoData As String = ""
Dim strRedoData As String = ""
#End Region
Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
If Not strUndoData <> "" Then
strUndoData = TextBox1.Text
End If
End Sub
Private Sub ctxMenu_UndoMePlease_OhYesPlease_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ctxMenu_UndoMePlease_OhYesPlease.Click
strRedoData = TextBox1.Text
TextBox1.Text = strUndoData
strUndoData = ""
ctxMenu_UndoMePlease_OhYesPlease.Enabled = False
ctxMenu_RedoMePlease_OhGodNotAgain.Enabled = True
End Sub
Private Sub ctxMenu_RedoMePlease_OhGodNotAgain_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ctxMenu_RedoMePlease_OhGodNotAgain.Click
TextBox1.Text = strRedoData
strUndoData = strRedoData
strRedoData = ""
ctxMenu_RedoMePlease_OhGodNotAgain.Enabled = False
ctxMenu_UndoMePlease_OhYesPlease.Enabled = True
End Sub
End Class