Send events to other form

Question

In my project there are near about ten forms ,and the forms are dependent with each other  respect to database.

Now suppose i have opened two form and made some changes in the data of one forms and update my database.
Now as i click on my first form It should get informed that the database has been updated and as client click on this form a messagebox should be appear saying
Please reload your form to get the latest changes.
How can i accomplish the task,Help me out please.