>>Another option is to change the code in your example as follows:
>>
>>

if empty(MyCheckBox.Value) && works both for 0 and .F.
>>   ....
>>endif

>>
>>HTH,
>
>Thanks Hilmar - that would be better than:-)
>

if ((vartype(checkbox.value)="L" and checkbox.value=.t.) or ;
>   (vartype(checkbox.value)="N" and checkbox.value=1)) and ;
>   !vartype(checkbox.value)="U"
>   checkbox=.t.
>endif

>
>It could go on forever

Yes, the code with empty() is definitely simpler, and I used this kind of code in several places. Of course, the idea solution would be to make sure the checkbox has the desired type - but I don't know how to solve the problem you reported, of VFP8 changing the type unexpectedly.

If you do manage to solve this, it seems better to me to keep the code as

if MyCheckBox.Value
...

or

if MyCheckBox.Value = 1
...

depending on whether you desire a logical or a numerical field. In this case, any unexpected change in the type would be quickly caught.