what is the correct way to determine that an AJAX call is successful?
I see in prototype.js
return !status || (status >= 200 && status < 300);
and in jQuery:
// IE error sometimes returns 1223 when it should be 204 so treat it as success, see #1450
return !xhr.status && location.protocol == "file:" ||
( xhr.status >= 200 && xhr.status < 300 ) || xhr.status == 304 || xhr.status == 1223;
which one is correct? If we don't use any Javascript library but write the AJAX in basic Javascript, which one should we use?