Last error: how to get?

Is there a simple way for me to programmatically know if an error has occurred during my script? (besides from writing a custom error handler?) I want to be able to know at the end of my script if any errors where thrown and then show a simple message. I know that if the error is fatal my script won't run to completion but that is ok as a fatal error in this case should be fatal. Is there some function like get_last_error()? Thanks, Jc