Using BeforeUpdate on an unbound text box

[Klatuu]

The easiest would be to use the Tag property.
When you load data from the tables into your form, put a line in that will
put the value into the control's tag property:
Me.ProductName.Tag = YourRecordset![PRODUCT_NAME]

Then change the code below:

Private Sub ProductName_BeforeUpdate(Cancel As Integer)
If(Not IsNull(DLookup("[ProductName]", _
"Products", "[ProductName] ='" _
& Me!ProductName & "'"))) Then
MsgBox "Product has already been entered in the database."
Cancel = True
Me!ProductName = Me.ProductName.Tag
End If

End Sub

Would you be able to provide more information or direction on the two methods
that you describe below?
Thanks,
KB

The OldValue property does not work for unbound controls. There are a few
ways you can accomplish this. One would be to use the Tag property of the
control, another would be to create your own property and use that. Also,
the Undo method does not apply to unbound controls.

I am building a form for the user to create a new record. Because the data
that is entered is for several different tables, none of the fields are
bound. Some of the fields are loaded with default values when the form is
opened (e.g. the IDnumber field is loaded with the next available ID number).
Once the data is entered and the user clicks the 'confirm' button, then I've
got code to parse the data to the various tables.
Now, I want to warn (and prevent) the user from creating a duplicate entry
in one of the tables.
Private Sub ProductName_BeforeUpdate(Cancel As Integer)
If(Not IsNull(DLookup("[ProductName]", _
"Products", "[ProductName] ='" _
& Me!ProductName & "'"))) Then
MsgBox "Product has already been entered in the database."
Cancel = True
Me!ProductName.Undo
End If
End Sub
I used this exact same code (just changed the field and table names). This
The Undo statement does not appear to work. Is this because the txt box is
unbound? If this is the case, how could I modify the code to revert back to
the old value?
Thanks for your help,
KB

[Klatuu]

The OldValue property does not work for unbound controls. There are a few
ways you can accomplish this. One would be to use the Tag property of the
control, another would be to create your own property and use that. Also,
the Undo method does not apply to unbound controls.

I am building a form for the user to create a new record. Because the data
that is entered is for several different tables, none of the fields are
bound. Some of the fields are loaded with default values when the form is
opened (e.g. the IDnumber field is loaded with the next available ID number).
Once the data is entered and the user clicks the 'confirm' button, then I've
got code to parse the data to the various tables.
Now, I want to warn (and prevent) the user from creating a duplicate entry
in one of the tables.
Private Sub ProductName_BeforeUpdate(Cancel As Integer)
If(Not IsNull(DLookup("[ProductName]", _
"Products", "[ProductName] ='" _
& Me!ProductName & "'"))) Then
MsgBox "Product has already been entered in the database."
Cancel = True
Me!ProductName.Undo
End If
End Sub
I used this exact same code (just changed the field and table names). This
The Undo statement does not appear to work. Is this because the txt box is
unbound? If this is the case, how could I modify the code to revert back to
the old value?
Thanks for your help,
KB