A complete request is not necessarily a successful request, and
your handler for the load event should check the status code
of the XMLHttpRequest object to ensure that you received an
HTTP “200 OK” response rather than a “404 Not Found” response,
for example.
There are three ways that an HTTP request can fail to complete,
and three corresponding events. If a request times out, the
timeout event is triggered. If a request is aborted, the abort
event is triggered. Finally, other network errors, such as too
many redirects, can prevent the completion of a request, and
the error event is triggered when this happens.
your handler for the load event should check the status code
of the XMLHttpRequest object to ensure that you received an
HTTP “200 OK” response rather than a “404 Not Found” response,
for example.
There are three ways that an HTTP request can fail to complete,
and three corresponding events. If a request times out, the
timeout event is triggered. If a request is aborted, the abort
event is triggered. Finally, other network errors, such as too
many redirects, can prevent the completion of a request, and
the error event is triggered when this happens.