I need to prompt a user to save their work when they leave a page. I've tried onbeforeunload but I need to show a styled prompt not the usual dialog box. Facebook has managed to achieve this (if you have a Facebook account, edit your profile info and go to another page without saving and you get a styled prompt). I've also tried jquery unload but there doesn't seem to be a way to stop the unload event from propagating.

Take a closer look at what Facebook is doing: you get a prompt if you click a link on the page, but nothing when entering a new URL in the address bar, clicking a bookmark, or navigating Back in your browser's history.

If that works for you, it's easy enough to do: simply add a click event handler to every link on the page, and trigger your stylized confirmation from it. Since these handlers will get called prior to the start of any navigation events triggered from within the page itself, you can pretty much do whatever you want in the handler - save data, cancel the event entirely, record the intended destination and postpone it 'till after they confirm...

However, if you do need or want to respond to navigation events triggered externally, you'll have to use onbeforeunload. And yes, the dialog is crappy, and you can't cancel the event - that's the price we pay for all the scandalous idiots abusing such features back in the '90s. Sorry...