>The code look like this..
>
>LPARAMETERS vNewVal
>DODEFAULT(vNewVal)
>
>IF vNewVal <<<<----- failed line (because it pass as an numeric)
>
> dosometing
>
>ENDIF
>
>
>--------
>The problem is on some computer (some Windows 98, ME, 2000) an error message
>occur. (the message occur only when we adding object in the INIT method of the form)
>
>We test the application on another computer (win 98) using the network (so application and data on the failed comptuter). It work ok!
>
>
>Thanks!
>
>Luc

---

Then i don't know what is the problem.
This should work.
Are you not saying setall('visible',numeric value) or something like that?

But about the basic problem, why would you have a _assgin method on the visible property. It is .t. when you start the form, and it only changes when you do that.
If you want to use it for pageframes, then look at the uienable event of the object in the help.