Hi Larry:

>In the code for the interactivechange event of the checkbox, I've got:
>
>THISFORM.txtBoxFoo.VALUE='3'

Whilst I would be more inclined to actually do a CM "replace" on the data source for your text box, the problem here appears to be that you are only setting the textbox's value using vanilla VFP <s>. With the CM enhanced binding, you really need to set a control's value using the control's SetValue() method (see CM help). This ensures that the value gets written to the control's datasource.

HTH