HttpStatusCodes

Success
200 OK 201 CREATED 202 Accepted 203 Partial Information 204 No Response

File Trouble
400 Bad request 401 Unauthorized 402 PaymentRequired 403 Forbidden 404 Not found

Redirection
301 Moved 302 Found 303 Method 304 Not Modified

Server Trouble
500 Internal Error 501 Not implemented 502 Service temporarily overloaded 503 Gateway timeout 503

the HTTP status codes: http://www.w3.org/Protocols/HTTP/HTRESP.html