Changing text based on checkbox value

[Elliot M. Rodriguez]

I'm attempting to edit the OnBeforeChange event for a simple checkbox so
that when its true, a text box fills with the text from another textbox on
my form.

When I use the following code:

If e.Operation = "Delete" Then

Return

End If

If e.Source.text = "true" Then

Dim nodTarget As IXMLDOMNode =
thisXDocument.DOM.selectSingleNode("/notificationform/txtStoreName")

nodTarget.text = "blah"

End If

I get Object Reference errors, and in debugging, nodTarget is always
"nothing".

notificationform is the name of the parent datasource group, and
txtStoreName is the name of my textbox.

What am I doing wrong? Any help is appreciated. Thanks.

 

[Elliot M. Rodriguez]

I ended up doing this through the designer using rules... but how can I do
it programmatically?