>>
>>For the controls on the form

>>Thisform.setall("Enabled", .f.)
>>* or
>>FOR EACH loControl IN Thisform.Controls
>>  IF PEMSTATUS(loControl ,"Enabled",5) && Does the enabled property exist?
>>     loControl.Enabled = .F.
>>  ENDIF
>>ENDFOR

You'll have to add more complicated logic to drill further down if there are containers on the form.
>
>Thanks Sergey, this gets more interesting...
>What control doesn't have an enabled property? Hyperlink is all I could find.

I see that Nadya answered your question already. I would like to add that even one control w/o the property you're accessing/changing will breake the code if you don't check for the property existence.