ajax.readyState (HTTP state value)
0 - (uninitialized) yet call send () method
1--: (loading) has been called send () method, a transmission request is
2 - (Loaded) send () method execution is completed, the entire response has been received
3 - (interactive) response is being parsed
4 - (complete) response content analysis is complete, you can call the client
ajax.status (HTTP status code)
1XX- requests received, continue processing
2XX- operate successfully received, analyzed, accepted
3XX- complete this request must be processed further
4XX- request contains a syntax error or can not be completed
5XX- server to perform a perfectly valid request failed
100 customers must continue to request
101 customer server converts the request of the HTTP protocol version
200- successful transaction
201- prompted know the URL of the new file
202- accept and process, but the process is not completed
203- return uncertain or incomplete information
204 - request received but no information is returned
to complete the request 205- server, the user agent must reset the current document has been visited
206- server has completed some users gET request
300 may request resources in several places to get
301 deletion request data
302 found in other address request data
303 customers are advised to visit another URL, or access method
304- client has performed a gET, but the file does not change
the resource 305 requested from the server must be specified address
306- ago a HTTP version of the code used in the current version is no longer used
307- declare a temporary resource request deletion
400 - Bad request, such as syntax errors
401 requesting authorization failed
402- to keep in force ChargeTo head in response to
403 requests are not allowed
404 file not found, query or URl
405 - the user is not in the process of Request-Line fields defined Xu
406- The user sends Accept drag, the requested resource is inaccessible
407- 401 Similarly, the user must first be authorized on the proxy server
408 the client request is not completed within a user-specified time hungry
The current state of the resource 409, the request can not be completed
no longer on the resource server 410 and no further reference address
411- Content-Length server rejected the user-defined attribute request
412- request one or more header fields in the current request error
size larger than the requested resource 413- server allows the
resource server 414- requested URL is longer than the allowed length of
415 does not support the requested resource format requested item
416 the request including a range header field of the request is not within the current range indicates resources requested value, If-Range request nor a request header field
417- Expect server does not satisfy the request header field specifies the expected value, if a proxy server may be a server can not satisfy the request
500 generates an internal server error
501 server does not support request function
502- server is temporarily unavailable, and sometimes to prevent system overload
503- repair server is overloaded or suspended
504- overload mark, use another gateway server in response to a user or service, a long wait time setting value
505- server reject the request or does not support the first middle branched HTTP version
