Android : Open new class/activity on button click in android

How to open another activity on button click? So now my app has one main window ( when you run the app ). Then there is a menu whit some buttons and when I click on some button is open another activity for this button. So I have one form which user must enter his details but now I want to click on button continue and open another activity where he must enter some more info. Now when this button is clicked the info goes into database. I know how to add more activities on normal page like main where I have only buttons but on this one I don't really know. Here is the code

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.reservation);

    editText1 = (EditText) findViewById(R.id.personName);
    editText3 = (EditText) findViewById(R.id.personPhone);
    editText2 = (EditText) findViewById(R.id.personEmail);
    editText4 = (EditText) findViewById(R.id.personComment);
    txtDate = (EditText) findViewById(R.id.datePicker);
    //txtTime = (EditText) findViewById(R.id.txtTime);
    numberOfPeoples = (EditText) findViewById(R.id.numberOfPeoples);

    btnCalendar = (Button) findViewById(R.id.btnCalendar);
    btnMenues = (Button) findViewById(R.id.continueWithReservation);


    btnMenues.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            Name = editText1.getText().toString();
            Phone = editText3.getText().toString();
            Email = editText2.getText().toString();
            Comment = editText4.getText().toString();
            DateTime = txtDate.getText().toString();
            numberOfPeople = numberOfPeoples.getText().toString();
            new SummaryAsyncTask().execute((Void) null);
        }
    }); 
}

class SummaryAsyncTask extends AsyncTask<Void, Void, Boolean> {

    private void postData(String Name, String Email, String Phone,
            String Comment, String DateTime, String numberOfPeople) {

        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://link.to.php.file");

        try {
            ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(4);
            nameValuePairs.add(new BasicNameValuePair("Name", Name));
            nameValuePairs.add(new BasicNameValuePair("Email", Email));
            nameValuePairs.add(new BasicNameValuePair("Phone", Phone));
            nameValuePairs.add(new BasicNameValuePair("Comment", Comment));
            nameValuePairs.add(new BasicNameValuePair("Date", DateTime));
            nameValuePairs.add(new BasicNameValuePair("numberOfPeople", numberOfPeople));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse response = httpclient.execute(httppost);
        }
        catch(Exception e)
        {
            Log.e("log_tag", "Error:  "+e.toString());
        }
    }

    @Override
    protected Boolean doInBackground(Void... params) {
        postData(Name, Email, Phone, Comment, DateTime, numberOfPeople );
        return null;
    }

}

So what I can put in setOnClickListener to go on next activity?

Update: If I change this

public void onClick(View v) {
            Name = editText1.getText().toString();
            Phone = editText3.getText().toString();
            Email = editText2.getText().toString();
            Comment = editText4.getText().toString();
            DateTime = txtDate.getText().toString();
            numberOfPeople = numberOfPeoples.getText().toString();
            new SummaryAsyncTask().execute((Void) null);
        }

to this

public void onClick(View v) {
        Intent intent = new Intent(MainActivity.this, Contacts.class);
        startActivity(intent);

    }

How to keep the information that user is added so far for next activity and save in DB after he finish with second activity?