Android : How to convert this inner AsyncTask in outer one?

I created this AsyncTask inner class and now i want to make it outer. Here is the code:

    private class DownloadDataFromServer extends AsyncTask<String, Integer, String> {
        ProgressDialog dialog;
        boolean connErr = false;
        boolean soErr = false;

        @Override
        protected void onPreExecute() {
            dialog = new ProgressDialog(HomePage.this); !!!!PROBLEM!!!!
            dialog.setIndeterminate(false);
            dialog.setMax(100);
            dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            dialog.setCancelable(false);
            dialog.setTitle("Download");
            dialog.setMessage("Updating...");
            dialog.show();

            super.onPreExecute();
        }

        @Override
        protected String doInBackground(String... urls) {
            // do something
        }

        protected void onProgressUpdate(Integer... progress) {
            // Update the progress
            dialog.setProgress(progress[0]);
        }

        @Override
        protected void onPostExecute(String result) {
            if (connErr || soErr) {
                String msg = "Bad connection";
                AlertDialog.Builder builder;
                builder = new AlertDialog.Builder(HomePage.this); !!!!PROBLEM!!!!
                builder.setCancelable(false);
                builder.setTitle("Connection timeout");
                builder.setMessage(msg);

                builder.setPositiveButton("Retry", new DialogInterface.OnClickListener(){
                    @Override
                    public void onClick(DialogInterface dialog, int which)
                    {
                        dialog.dismiss();
                        new DownloadDataFromServer().execute(new String[] { "http://www.example.com" });
                    }
                });

                builder.setNegativeButton("Exit", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                        finish(); !!!!PROBLEM!!!!
                    }
                });         
                AlertDialog dialog = builder.create();
                dialog.show();
            } else {
                if (Integer.parseInt(result) <= 0) {
                    Toast.makeText(getBaseContext(), "Error!", Toast.LENGTH_SHORT).show(); !!!!PROBLEM!!!!
                } else {
                    Toast.makeText(getBaseContext(), "OK!", Toast.LENGTH_SHORT).show(); !!!!PROBLEM!!!!
                }
            }
            dialog.dismiss();
        }
    }

Please note "!!!!PROBLEM!!!!" strings in the above code: there are all the errors that i get. I tried to apply some workarounds but finally i could not make it working. In addition i also have to use

private Database db = new Database(this);

but i do not know what to put in place of "this". Please help me to convert this inner class in the right way.