First off, I seem to recall that status should be '404 Not found', not only the number.

Secondly, for a message to display, you will have to actually print something. Such as

print $WP->h1('404 Page not found');
[download]

What you mean with 'for the particular browser you are using' I am not sure - is it that IE replaces errors with its own "friendly" pages? You should be happy if it does not for you, that is a really annoying "feature" that sometimes hides important information to the user.

If you really want it to display the built-in message, I'm not sure why it doesn't trigger. Maybe because some header is missing, may be because it recognizes that it is a script, or at least not a plain HTML doc (on the files extension).

You could, of course, redirect (IE) users to some bogus URL like so:

print $WT->redirect('/showIE404')
  if($browser eq 'IE');
[download]

I *hate* browser checks, but if you must, you must.

What I really think you should do is have a fun 404 page instead, like SGI's (I think) that showed a random very sad and crying baby when a page could not be found. Of course with the proper status code. Or maybe one of my personal favourites, http://icculus.org/404 (got it from someone here, was it Aristotle? Whoever it was, thanks again! :) ). And oh, try reloading it for new messages.

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