Most professional applications have an Undo menu option under the Editmenu. If you want to have an undo feature for every text box, you may thinkyou need to create a variable to hold the old value for every field. Fortunately,Windows takes care of this for you. With a call to the Windows API functionSendMessage(), you can have the old value put back into the text box. Createa menu item called Undo and add this code:
Sub mnuUndo_Click () Call TextUndo(Screen.ActiveControl) End Sub TextUndo() is responsible for performing the undo: Declare Function SendMessage Lib "User" _ (ByVal hWnd As Integer, ByVal wMsg As Integer, _ ByVal wParam As Integer, lParam As Any) As Long Sub TextUndo (ctlControl As Control) Dim lReturn As Long Const EM_UNDO = &H417 If TypeOf Screen.ActiveControl Is TextBox Then lReturn = SendMessage(ctlControl.hWnd, _ EM_UNDO, 0, 0&) End If End SubBecause some third-party controls also support the undo message,place TextUndo() in a separate routine to make it easy to change this onefunction by adding the Class name of the third-party control. If you do,there will be no reason to change all the calls to the SendMessage() function.
