Getting Error: You can't assign a value to this object.

[cowboy]

Getting Error saying:
Run-time error '2448':
You can't assign a value to this object.

I have tried:

If IsNull(Me![Right Side DI Depth]) Then
Me!txtZB.value = Me!txtZA.value
End If

If IsNull(Me![Right Side DI Depth]) Then
Me![Left Side DI Depth] = Me!txtZA.value
End If

I have attached a picture with the watches I had running. I just want to test txtZB and if it is Null I want it to take the value of txtZA. txtZB has the control source of [Left Side DI Depth] and txtZA control source [Right Side DI Depth]

Thanks for help.

[pbaldy]

Where is the code? It would need to be in the format event of the section containing the control, not the open event.

[cowboy]

Private Sub Detail_Format(Cancel As Integer, FormatCount As Integer)
ShowPage
End Sub

calls the function that has the code in it.

[cowboy]

I posted the wrong picture in the first post, here are some pictures showing the actual values for the watch and a picture of the error message.