AsyncTask

public class MyAsyncTask extends AsyncTask<String,Integer,String>{
        Context context;
        ProgressDialog pD ;
        public MyAsyncTask(Context c){
            context =c;
        }
        @Override
        protected String doInBackground(String... urls) {
            String retVal = "";
            HttpGet httpget = new HttpGet(urls[0]);
            AndroidHttpClient ahttp = AndroidHttpClient.newInstance("Android");
            try{
                String result = ahttp.execute(httpget, new BasicResponseHandler());
                retVal = result;
            }catch(ClientProtocolException e){
                Toast.makeText(context, "Network error", Toast.LENGTH_SHORT).show();
                retVal = "W";
            }catch(IOException ee){
                Toast.makeText(context, "Network error", Toast.LENGTH_SHORT).show();
                retVal = "W";
            }finally{
                if(ahttp != null){
                    ahttp.close();
                }
            }
            if(!retVal.equals("W")){
                return retVal;
            }
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            pD.dismiss();
            if(result != null){
                if(!result.contains("error")){
                    if(result.equals(password)){
                        Intent i = new Intent(MainActivity.this,TysActivity.class);
                        i.putExtra(EXTRA_USER, username);
                    }else{
                        Toast.makeText(context, "Wrong password", Toast.LENGTH_SHORT).show();
                    }
                }else{
                    Toast.makeText(context, "Wrong username", Toast.LENGTH_SHORT).show();
                }
            }
        }

        @Override
        protected void onPreExecute() {
            pD = new ProgressDialog(MainActivity.this);
            pD.setMessage("Please wait.....");
            pD.show();
        }
    }