If you're displaying content to the user, it doesn't make sense to redirect right away, which is what the header("Location: URL") method does for you. The user wouldn't have any chance at reading your error messages.
I suggest you use javascript and/or a meta-refresh tag if you'd like to redirect the user to a different page after one page is loaded for a given amount of time.
Take care,
Nik
http://www.bigaction.org/