i am getting errors!!!!

package james.blogreader;

import android.app.ListActivity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONObject;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;


public class MainListActivity extends ListActivity {

    protected String[] mBlogPostTitles;
    public static final int NUMBER_OF_POSTS = 20;
    public static final String TAG = MainListActivity.class.getSimpleName();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_list);

        if (isNetworkAvailable()) {
            GetBlogPostsTask getBlogPostsTask = new GetBlogPostsTask();
            getBlogPostsTask.execute();
        }
        else {
            Toast.makeText(this,"No network detected, check your internet settings.",Toast.LENGTH_LONG).show();
        }

    }

        //Toast.makeText(this,getString(R.string.no_items),Toast.LENGTH_LONG).show();
    private boolean isNetworkAvailable() {
        ConnectivityManager manager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        return false;
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main_list, menu);

        boolean isAvailable = false;
        if (networkInfo != null && networkInfo.isConnected()){
            isAvailable = true;
        }
        return isAvailable;
    }


    private class GetBlogPostsTask extends AsyncTask<Object,Void,String> {
        @Override
        protected String doInBackground(Object... arg0) {
            int responceCode = -1;

            try {
                URL blogFeedUrl = new URL("http://blog.teamtreehouse.com/api/get_recent_summary/?count=" + NUMBER_OF_POSTS);
                HttpURLConnection connection = (HttpURLConnection) blogFeedUrl.openConnection();
                connection.connect();

                 responceCode = connection.getResponseCode();
                if (responceCode == HttpURLConnection.HTTP_OK) {
                    InputStream inputStream = connection.getInputStream();
                    Reader reader = new InputStreamReader(inputStream);
                    int contentLength = connection.getContentLength();
                    char[] charArray = new char[contentLength];
                    reader.read(charArray);
                    String responceData = new String(charArray);
                    JSONObject jsonResponce= new JSONObject(responceData);
                    String status = jsonResponce.getString("status");
                    Log.v(TAG, status);
                    JSONArray jsonPosts = jsonResponce.getJSONArray("posts");
                    for (int i = 0;i < jsonPosts.length();i++) {
                        JSONObject jsonPost = jsonPosts.getJSONObject(i);
                        String title = jsonPost.getString("title");
                        Log.v(TAG,"Post " + i + ": " + title);
                    }
                }
                else {
                    Log.i(TAG,"Unsuccessful HTTP Responce Code : " + responceCode);
                }

            }
            catch (MalformedURLException e) {
                Log.e(TAG,"Exception caught",e);
            }
            catch (IOException e) {
                Log.e(TAG,"Exception caught", e);
            }
            catch(Exception e){
                Log.e(TAG,"Exception caught", e);
            }
            return  "Code: " + responceCode;
        }


    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        return id == R.id.action_settings || super.onOptionsItemSelected(item);
    }
}

cannot resolve symbol networkInfo

field mBlogPostTitles is never used
Variable networkInfo is never used