I've had customers complain that when textboxes are disabled or even just readonly they can't read the value in them. To get around things like that I have a variable that tracks when things are supposed to be read-only. Then every event for those controls just gets skipped when that variable is set to true. So, something like this:
Dim boolMakeReadOnly as Boolean = True
Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
If boolMakeReadOnly Then Return 'This exits the event
'Original code for the submit button (gets skipped if boolMakeReadOnly is true)
End Sub