>Hi
>
>Can anyone explain what is the difference between 1.Default Data Session and 2.Private Data Session?
>

A slightly different explanation than Hilmar's:

A form with a Private Datasession has its own data environment which consists of tables, cursors, views and SET settings. Changing things in this datasession do not affect other forms with private datasessions.

A form with a Default Datasession inherits the datasession of the form that called/created the form (or VFP's default datasession if not called from another form).

>2. Where to use LockScreen? Because sometime when I click on any object the form slightly shake.

Lock the screen, do your processing and then unlock.

>3. Is it safe to use SP2 now? As I am not fully aware of it.

As far as I know it is safe. I have it running on a couple projects without a problem.

>4. In case of SP2 is there any major changes in project?
>

Not that I can think of off the top of my head.

>Thanks/Regards
>
>Saifuddin