public class LoginActivity extends Activity implements OnClickListener {

class AttemptLogin extends AsyncTask<String, String, String> {

    boolean failure = false;
    String success;
    AlertDialog.Builder builder = new AlertDialog.Builder(
            LoginActivity.this);

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(LoginActivity.this);
        pDialog.setMessage("Logging in. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(false);
        pDialog.show();
    }

    @Override
    protected String doInBackground(String... args) {

        String userName = edtUname.getText().toString();
        String docID = edtPass.getText().toString();
        try {
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("usrName", userName));
            params.add(new BasicNameValuePair("dcID", docID));
            Log.d("request!", "starting");

            LOGIN_URL = LOGIN_URL + " &username=" + userName
                    + " &password=" + docID;

            JSONObject json = jsonParser.getJSONFromUrl(LOGIN_URL);
            success = json.optString("auth");

            if (success.equals("Yes")) {

                Log.d("Successfully Login!", json.toString());

                return json.optString(TAG_MESSAGE);

            } else {
                return json.optString(TAG_MESSAGE);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    protected void onPostExecute(String message) {

        pDialog.dismiss();

        if (success.equals("Yes")) {
            builder.setMessage("do you want to save your credentials ?")
                    .setCancelable(false)
                    .setPositiveButton("Yes",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,
                                        int id) {
                                    String userName = edtUname.getText()
                                            .toString();
                                    String docID = edtPass.getText()
                                            .toString();

                                    sharedpreferences = getSharedPreferences(
                                            MyPREFERENCES,
                                            Context.MODE_PRIVATE);

                                    Editor editor = sharedpreferences
                                            .edit();

                                    editor.putString("usrIdkey", userName);
                                    editor.putString("usrPasskey", docID);
                                    editor.commit();

                                    Intent ii = new Intent(
                                            LoginActivity.this,
                                            PatientDetailsActivity.class);
                                    startActivity(ii);

                                    Toast.makeText(getApplicationContext(),
                                            "Login Successfully...",
                                            Toast.LENGTH_SHORT).show();

                                    finish();

                                }
                            })
                    .setNegativeButton("No",
                            new DialogInterface.OnClickListener() {
                                public void onClick(DialogInterface dialog,
                                        int id) {

                                    SharedPreferences sharedpreferences = getSharedPreferences(
                                            "MyPrefs", Context.MODE_PRIVATE);
                                    SharedPreferences.Editor editor = sharedpreferences
                                            .edit();
                                    editor.clear();
                                    editor.commit();

                                    Intent ii = new Intent(
                                            LoginActivity.this,
                                            PatientDetailsActivity.class);
                                    startActivity(ii);
                                    finish();

                                    // Action for 'NO' Button
                                    dialog.cancel();
                                }
                            });

            // Creating dialog box
            AlertDialog alert = builder.create();
            // Setting the title manually
            alert.setTitle("User Credentials");
            // Showing alert dialog box
            alert.show();
        }
        if (success.equals("Yes")) {

        } else {
            Toast.makeText(LoginActivity.this, "Login Failed...",
                    Toast.LENGTH_SHORT).show();
        }

    }
}