I have some data in the database and values can be added on demand. so when ever the value added to the database i need to promt that message to all users which are accessing my website, so how can i acheive this please help me .
Impossible, and thank god that it is impossible.
But it is possible to POLL for information, especially using Ajax technology. I would research a bit in that area, I'm sure you'll find a cookiecutter solution quite quickly depending on using what technology your website is built. Even JQuery has options for it I believe.