To add to Hilmar's suggestion, in the queryunload() method you can inspect the form's releaseType property to determine if the close box was pressed, something like:

* queryUnload()
if thisform.releaseType = 1
    return .f.
endif

>I would like to know how to prevent my user from closing the project using the "Close (X)" at the top rightmost side of VFP screen. I am wondering if this can be disabled.
>
>Thanks a lot,
>
>Nerissa