The third parameter is the class name on which the object is based, not the Visual FoxPro base class for the object. So if your textboxes are based on 'mytxt' class than change third parameter to 'mytxt'.

>When I run the following code, my textboxes are not enabled. but if i run thisform.mytext.enabled = .t., then the textboxes are enabled. Anything wrong with this code?:
>
>thisform.setall('ENABLED',.T.,'Textbox')