我是Android應用程序開發(fā)的新手，我需要兩個文本框用戶名和密碼，它將登錄到服務器并使用php頁面與數(shù)據(jù)庫進行檢查，如果登錄成功，則轉(zhuǎn)到下一個屏幕，否則顯示一個msg框顯示登錄錯誤我該怎么辦？public void postData() {    // Create a new HttpClient and Post Header    HttpClient httpclient = new DefaultHttpClient();    HttpPost httppost = new HttpPost("http://google.com");    EditText tw =(EditText) findViewById(R.id.EditText01);    try {        // Add your data        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);        nameValuePairs.add(new BasicNameValuePair("id", "12345"));        nameValuePairs.add(new BasicNameValuePair("stringdata", "AndDev is Cool!"));        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));        // Execute HTTP Post Request        HttpResponse response = httpclient.execute(httppost);        int status = response.getStatusLine().getStatusCode();        tw.setText(status);    } catch (ClientProtocolException e) {        tw.setText(e.toString());    } catch (IOException e) {        tw.setText(e.toString());    }}