I have a text field which is empty, but when you click in it it has some suggestions from previous inputs.
Which JavaScript event is fired if i choose one of them wi
An incredibly useful tool that should help you solve your problem is Visual Event 2. Basically, for any element on your screen, it will tell you which Javascript evenets that element is registered for.
It's a bookmarklet, so what you do is drag this the to your bookmarks bar, navigate to the page you're curious about, and then click then link. Presto! Detailed information about the currently registered Javascript events.
As @smerny said, there's a good chance that's not even Javascript, and is just native browser functionality. That being said, you could probably implement your own version pretty easily.