>Fabio,
>
>His code is not formally wrong. Bitwise constants like this can be, and are, added together all the time. If I had the K&R C book handy I'd point you to some examples.

this book is wrong.

>
>I'd argue that Carlos' use of three constants is in fact clearer (although I'd recommend using the #define constants from foxpro.h) that 3 specific messagebox flags are being sent to the function.
>

>Your suggestion to use MB_SYSTEMMODAL does violate the Windows standard guidelines because the message Khubaib is trying to display is not critical to the operation of the machine at the O/S level. It is critical only to his app.
>

I don't suggest anything, I have answered only to the question.
However many of the Windows's standards are wrong.

>>>

>>>ttt = Messagebox('please check your serialno '+Chr(10)+'Your Serial # is ';
>>>+Alltrim(Str(scode)),4+32+4096, product)
>>>

>>
>>This work but it is formally wrong.