A.200 B.202 C.400 D.404
A.1表示新創(chuàng)建 B.2表示初始化 C.3表示發(fā)送數(shù)據(jù)完畢 D.4表示接收結(jié)果完畢
A.xmlHttpRequest. myCallback = onreadystatechange; B.xmlHttpRequest.onreadystatechange (myCallback); C.xmlHttpRequest.onreadystatechange (new function(){myCallback }); D.xmlHttpRequest.onreadystatechange = myCallback;