I was working on old VB6 apps, and yes there were validating events which couldn't even allow the user to close the application using the "X" button at the top of the window.

Though VB.NET also has a "validating" event I am still not sure how is to be used properly because I don't want to confuse the user of my application by locking the application at just the currently selected field if the validation fails

Can you recommend me some good examples or tutorials for using validating event in VB.NET?