public void loginPost(View view){
  String username = usernameField.getText().toString();
  String password = passwordField.getText().toString();


  try{


  String link="http://mwssong.esy.es/android/Login.php";
  String data  = URLEncoder.encode("username", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8");
  data += "&" + URLEncoder.encode("password", "UTF-8") + "=" + URLEncoder.encode(password, "UTF-8");

  URL url = new URL(link);
  URLConnection conn = url.openConnection();

  conn.setDoOutput(true);
  OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());

  wr.write( data );
  wr.flush();

  BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));

  StringBuilder sb = new StringBuilder();
  String line = null;

  // Read Server Response
  while((line = reader.readLine()) != null)
  {
     sb.append(line);
     break;
  }

  if(sb.toString()=="admin")
      new AdminScreen();
  else if(sb.toString()=="Customer")
  {

      Intent myIntent(view.getContext(),AdminScreen.class);
      startActivity(myIntent);
  }
  else
      status.setText(sb);
  }
  catch(Exception e){
      status.setText("Exception:   " + e.getMessage());
  }

Intent myIntent(view.getContext(),AdminScreen.class);
      startActivity(myIntent);