Partly user training, partly database design.

The user can hit <Esc><Esc> to undo what they've done on the form.

In addition, or instead, you can put VBA code in the Form's BeforeUpdate event
to check that everything is filled in:

Private Sub Form_BeforeUpdate(Cancel as Integer)
Dim iAns As Integer
If IsNull(Me!ThisControl) Then
  Cancel = True
  iAns = MsgBox("Fill in ThisControl or click Cancel to erase form", _
    vbOKCancel)
  If iAns = vbCancel Then
     Me.Undo
  End If
End If
<etc for the other controls>
End Sub

            John W. Vinson [MVP]

In addition to John's suggestions, you can add an <Undo> command button.

Regards

Jeff Boyce
Microsoft Office/Access MVP

Put a cancel button on the form call it cmdCancel.
--type the word Cancel onto the button itself
--in design view of the form click the cancel button
--on the property dialog, on the event tab
--find On Click, click the button with the ellipsis(...) for On Click
--choose Code builder
--the VBA editor opens
--You will see
   Private Sub cmdCancel_Click()
   End Sub
type in these lines
If Me.Dirty = True Then
   Me.Undo
End If
DoCmd.Close acForm, Me.Name

The whole thing will look like this
Private Sub cmdCancel_Click()
If Me.Dirty = True Then
   Me.Undo
End If
DoCmd.Close acForm, Me.Name
End Sub

When the user clicks Cancel, any changes will be undone and the form will
close.

Jeanette Cunningham