Changes

When Firefox cannot display a requested web page because of a network error, it currently shows a network error page. This page describes the problemand gives advice on how to fix it, but it currently offers only one "tool" for resolving the problem: the "Try Again" button. This is of limited utility, in fact, and for a large class of errors, this is the one thing guaranteed not to work (cfeg. misspelled URLs). A better network error page would provide a variety of the user with useful tools for resolving towards guiding them to the problemcontent they wanted.

Additionally, web pages that result in 404 errors have a lot in common with network error pages, except that the error page is provided by the server. In many case cases this is a default 404 error page for the server which is not very helpful. The other major browsers will substitute a browser-provided 404 error page in many cases (the typical rule seems to be not to override server-provided error pages over about 500 bytes in length, since those are likely to be customized). Firefox should provide similar functionality.