09-16 10:09:05.529: E/AndroidRuntime(26221): FATAL EXCEPTION: AsyncTask #1
09-16 10:09:05.529: E/AndroidRuntime(26221): java.lang.RuntimeException: An error occured while executing doInBackground()
09-16 10:09:05.529: E/AndroidRuntime(26221):    at android.os.AsyncTask$3.done(AsyncTask.java:299)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at java.util.concurrent.FutureTask.run(FutureTask.java:239)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at java.lang.Thread.run(Thread.java:841)
09-16 10:09:05.529: E/AndroidRuntime(26221): Caused by: java.lang.NullPointerException
09-16 10:09:05.529: E/AndroidRuntime(26221):    at com.databaseaar.Login_new$AttemptLogin.doInBackground(Login_new.java:82)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at com.databaseaar.Login_new$AttemptLogin.doInBackground(Login_new.java:1)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
09-16 10:09:05.529: E/AndroidRuntime(26221):    at java.util.concurrent.FutureTask.run(FutureTask.java:234)
09-16 10:09:05.529: E/AndroidRuntime(26221):    ... 4 more
09-16 10:09:06.459: E/WindowManager(26221): Activity com.databaseaar.Login_new has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{42c25fb0 V.E..... R......D 0,0-684,192} that was originally added here
09-16 10:09:06.459: E/WindowManager(26221): android.view.WindowLeaked: Activity com.databaseaar.Login_new has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{42c25fb0 V.E..... R......D 0,0-684,192} that was originally added here
09-16 10:09:06.459: E/WindowManager(26221):     at android.view.ViewRootImpl.<init>(ViewRootImpl.java:452)
09-16 10:09:06.459: E/WindowManager(26221):     at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:258)
09-16 10:09:06.459: E/WindowManager(26221):     at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:73)
09-16 10:09:06.459: E/WindowManager(26221):     at android.app.Dialog.show(Dialog.java:287)
09-16 10:09:06.459: E/WindowManager(26221):     at com.databaseaar.Login_new$AttemptLogin.onPreExecute(Login_new.java:66)
09-16 10:09:06.459: E/WindowManager(26221):     at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
09-16 10:09:06.459: E/WindowManager(26221):     at android.os.AsyncTask.execute(AsyncTask.java:534)
09-16 10:09:06.459: E/WindowManager(26221):     at com.databaseaar.Login_new$1.onClick(Login_new.java:49)
09-16 10:09:06.459: E/WindowManager(26221):     at android.view.View.performClick(View.java:4475)
09-16 10:09:06.459: E/WindowManager(26221):     at android.view.View$PerformClick.run(View.java:18786)
09-16 10:09:06.459: E/WindowManager(26221):     at android.os.Handler.handleCallback(Handler.java:730)
09-16 10:09:06.459: E/WindowManager(26221):     at android.os.Handler.dispatchMessage(Handler.java:92)
09-16 10:09:06.459: E/WindowManager(26221):     at android.os.Looper.loop(Looper.java:137)
09-16 10:09:06.459: E/WindowManager(26221):     at android.app.ActivityThread.main(ActivityThread.java:5419)
09-16 10:09:06.459: E/WindowManager(26221):     at java.lang.reflect.Method.invokeNative(Native Method)
09-16 10:09:06.459: E/WindowManager(26221):     at java.lang.reflect.Method.invoke(Method.java:525)
09-16 10:09:06.459: E/WindowManager(26221):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1209)
09-16 10:09:06.459: E/WindowManager(26221):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1025)
09-16 10:09:06.459: E/WindowManager(26221):     at dalvik.system.NativeStart.main(Native Method)

public class Login_new extends Activity implements OnClickListener{
    private EditText user, pass;
    private Button bLogin;
    private ProgressDialog pDialog;

    JSONParser jsonParser = new JSONParser();

    private static final String LOGIN_URL = "http://xxxx.com/login_new2.php";
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_MESSAGE = "message";
    public static final String KEY_USERNAME ="username";

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login2);
        user = (EditText)findViewById(R.id.ET_email);
        pass = (EditText)findViewById(R.id.ET_password);
        bLogin = (Button)findViewById(R.id.btnLogin);
        //bLogin.setOnClickListener(Login_new.this);

    bLogin.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
        // TODO Auto-generated method stub
        switch (v.getId()) {
        case R.id.btnLogin:
            new AttemptLogin().execute();
        default:
            break;
        }}
        });
    }

    class AttemptLogin extends AsyncTask<String, String, String> {
        // public static final String KEY_USERNAME = null;
        boolean failure = false;

         protected void onPreExecute() {
             super.onPreExecute();
             pDialog = new ProgressDialog(Login_new.this);
             pDialog.setMessage("Attempting for login...");
             pDialog.setIndeterminate(false);
             pDialog.setCancelable(true);
             pDialog.show();
         }

        @Override
        protected String doInBackground(String... args) {
            int success;
            String username = user.getText().toString();
            String password = pass.getText().toString();
            try {
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("username", username));
                params.add(new BasicNameValuePair("password", password));

                 Log.d("request!", "starting");

                 JSONObject json = jsonParser.makeHttpRequest(LOGIN_URL, "POST", params);
                 Log.d("Login attempt", json.toString());

                // success tag for json
                 success = json.getInt(TAG_SUCCESS);
                 if (success == 1) {
                     Log.d("Successfully Login!", json.toString());

                 Intent ii = new Intent(Login_new.this,MainActivity.class);
                 ii.putExtra(KEY_USERNAME, username);
                 finish();
                 startActivity(ii);

                 return json.getString(TAG_MESSAGE);
                 }else {

                   return json.getString(TAG_MESSAGE);
               }
               } catch (JSONException e) {
                   e.printStackTrace();
            }
               return null;
    }

    protected void onPostExecute(String message) {
        pDialog.dismiss();
        if (message != null){
            Toast.makeText(Login_new.this, message, Toast.LENGTH_LONG).show();
            }
        } }}