There are error codes when something bad happens to a page but there is also a code when it loads correctly.
What browser code for a page when it loads like it should?
It should be HTTP code 200 ("Ok"). NB: This is on http level and has nothing to do with html. It only tells you that the requested content has been accessed correctly.
You can have a look at the RFC for the different HTTP codes. http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html