Advice on how to prompt for saving edits

I want to pick your collective brains on how to do something:

I have a page that has about 10 fields for display/edit.

If a user edits any of the data in any way, and trys to navigate away before saving I want a message to display saying "would you like to save your edits, yes (saves), no ignores.

Is there an easy way to do this?

For your body tag:
onbeforeunload="RunBeforeUnload()"

Then, make a function called RunBeforeUnload() that returns true if the page should navigate away or false if it should not.

Or instead of true/false you can force a postback to occur if that's your thing.

Thanks I'll play with it.