I have a form and I must notice user with alert() on exiting page while there are data in the form that had not been send.
I've read that opera has a lot of problems with this. Opera 11 that is, because I need take into account only last version.
So again, the alert should display on refresh, closing a tab, or closing whole browser.
It would be nice to set event directly to the <form>
element that would be launched on anything that leads to destroying this element.