华南俳烁实业有限公司

                                     xhr.onreadystatechange=f1;

                                     xhr.send(null);

                            b,發(fā)送post請(qǐng)求

                                     xhr.open('post');

                                     ...

                   step3 服務(wù)器端編寫處理請(qǐng)求的代碼

                   step4 在監(jiān)聽(tīng)器當(dāng)中，處理服務(wù)器返回的數(shù)據(jù)，

                   一般是通過(guò)XmlHttpRequest獲得數(shù)據(jù)之后，更

                   新頁(yè)面。

                                     function f1(){

                                               //只有狀態(tài)為4時(shí)，才能正確地接收服務(wù)器

                                               //返回的數(shù)據(jù)

                                               if(xhr.readyState == 4){

                                                        //獲得服務(wù)器返回的文本數(shù)據(jù)

                                                        var txt = xhr.responseText;

                                                        //通過(guò)dom，更新頁(yè)面