Sounds like I can stick with my advice to post the message in a new thread--probably NOT under Chatter--with such specifics as you included here will help you. As I said, the Internet gurus will probably miss this thread. :-)

Good luck!

>I meant the vfp data.In case, i am developing a digital on-line library system. I need to keep track the availability of the book shown on web page are alway accurate.Then i need to refresh the book status intervally....how could i implement it??