مشکل بررسی داشتن اینترنت (ارسال و دریافت دیتا)

سلام دوستان من فرمی دارم که به سایت باید وصل بشه . نام کاربری و رمز را چک بکنه و نتیجه را برگردونه

حالا مشکل من اینه دفعه اول که روی دکمه میزنم Main Thread Exception میده و میگه اتصال برقرار نیست ولی بار دوم جواب میده

 		btnLogin.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				checkconnect();
			}
		});

	private void checkconnect() {
		try {
			conMan = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
			mobile = conMan.getNetworkInfo(ConnectivityManager.TYPE_MOBILE)
					.getState();
			wifi = conMan.getNetworkInfo(ConnectivityManager.TYPE_WIFI)
					.getState();
			if (mobile == NetworkInfo.State.CONNECTED
					| mobile == NetworkInfo.State.CONNECTING) {
				get_users();
			} else if (wifi == NetworkInfo.State.CONNECTED
					| wifi == NetworkInfo.State.CONNECTING) {
				get_users();
			} else {
				G.selectMode = "offline";
				toast.Redtoast(ActivityLogin.this, "Wifi or Gprs Disable");
			}
		} catch (Exception e) {
		}
	}

	private void get_users() {

		try {
			String u, p;
				u = edtusername_login.getText().toString();
				p = edtpassword_login.getText().toString();
				LoginUser loginUser = new LoginUser();
				loginUser.GetUserData(ActivityLogin.this, u, p, user_error,
						loginguser);
				checkuserpass();
				
		} catch (Exception e) {
			Log.e(G.APP_LOG, "login error");
			e.printStackTrace();
		}
	}

	private void checkuserpass() {
		if (G.userList.size() <= 0) {
			toast.Redtoast(ActivityLogin.this, user_error);
		} else {
			G.GCode = G.userList.get(G.userList.size() - 1).getUs_GCode();
			G.GAccCode = G.userList.get(G.userList.size() - 1).getUs_GAccCode();
			toast.Bluetoast(ActivityLogin.this, "Get user pass ok");
			Intent intent = new Intent(ActivityLogin.this, ActivityMain.class);
			startActivity(intent);
			ActivityLogin.this.finish();
		}
	}

تابعی که در کلاس LoginUser اجرا میشه 

 private void Checkdata() {
			List<NameValuePair> params = new ArrayList<NameValuePair>();
			params.add(new BasicNameValuePair("uName", user));
			params.add(new BasicNameValuePair("uPass", pass));
			JSONObject json = jParser.makeHttpRequest(url_user, "POST", params);
			try {
				int success = json.getInt(TAG_SUCCESS);
				if (success == 1) {
					UserStruct userStruct = new UserStruct();
					String GCode = json.getString("GCode");
					userStruct.setUs_GCode(GCode);
					String GAccCode = json.getString("GAccCode");
					userStruct.setUs_GAccCode(GAccCode);
					G.userList.add(userStruct);
					pDialog.dismiss();
				}/*
				 * else { toast.Redtoast((Activity) context, user_error); }
				 */
			} catch (JSONException e) {
				toast.Redtoast((Activity) context, user_error);
				pDialog.dismiss();
			}
		}

public class JSONParser {

    static InputStream is   = null;
    static JSONObject  jObj = null;
    static String      json = "";


    public JSONParser() {

    }


    public JSONObject makeHttpRequest(String url, String method,
                                      List<NameValuePair> params) {
		HttpClient httpClient;
		HttpPost httpPost;
        try {

            // check for request method
            if (method == "POST") {
				httpClient = new DefaultHttpClient();
				httpPost = new HttpPost(url);
                if (params != null) {
                    httpPost.setEntity(new UrlEncodedFormEntity(params));
                }
                HttpResponse httpResponse = httpClient.execute(httpPost);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();

            } else if (method == "GET") {
				httpClient = new DefaultHttpClient();
                String paramString = URLEncodedUtils.format(params, "utf-8");
                url += "?" + paramString;
                HttpGet httpGet = new HttpGet(url);

                HttpResponse httpResponse = httpClient.execute(httpGet);
                HttpEntity httpEntity = httpResponse.getEntity();
                is = httpEntity.getContent();
            }

        }
        catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        catch (ClientProtocolException e) {
            e.printStackTrace();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            //BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
            BufferedReader reader = new BufferedReader(new InputStreamReader(is), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            is.close();
            json = sb.toString();
        }
        catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }
        try {
            jObj = new JSONObject(json);
        }
        catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }
        return jObj;
    }
}

ممنون میشم بگین چطوری جلوی دو بار کلیک را بگیرم برای ورود و با یک بار اطلاعات گرفته بشه و بررسی بشه