I put in return false; and it did nothing (using Chrome v22.0.1229.56 beta-m). You wouldn't want to return false anyways, alert is not defined as returning a value (see: https://developer.mozilla.org/en-US/docs/DOM/window.alert)
If you want to see what arguments are being passed, add a console.dir(arguments); to the code.
If you want to see what arguments are being passed, add a console.dir(arguments); to the code.