Trying to cancel texbox entry if duplicate (1 Viewer)

[Malcy]

Hi
I have one that is doing my head in.
I need to test that a Job Number has not been used before. If it has there is a very slight chance they might want to re-use it. The relevant bit of my code (in the BeforeUpdate event) is

' Verify if job number has already been used
    varJob = DLookup("lngJob", "tblJobs", "[strJobNo] = '" & Me.txtJobNo & "'")
    
' If job number has been already used check with user
    If Not IsNull(varJob) Then
       
' Advise user
        varResponse = MsgBox("This job number has already been used." & vbLf & vbLf & "Are you sure you want to re-use it?", vbYesNo, "Duplicate job number - Confirmation required")
        
        If varResponse = vbNo Then
            
            Cancel = True
            Undo

        End If
    End If
[\CODE]

When I run it and deliberately use a duplicated number it picks it up and gives me the message. When I say no it retains the entered number with the cursor flashing at the end of the number. I want it to remove the entered number and mae it clear another number needs to be entered.
What is it I am missing? It has been a long weekend so I guess I may kick myself when someone is able to point out the obvious :-)
Thanks for any input

 

[SOS]

Change it to

Me.YourControlName.Undo

or if you want the whole form reset

Me.Undo

 

[Malcy]

Thanks
That sort of three quarters did the trick in that it throws the focus back onto the textbox and allows everything to be written over.
Ideally I would also like it to null off the previous entry so the new entry is "fresh" rather than just highlighting it so as to enable overwriting. I will try tinkering further.
Thanks for the help
Best wishes