Android : 1 how to call back second activity to first with all ready exisst Intent Object?

here i am provide my second activity code on button click event here i am try to existing In any method for that to call ...?

1. List item

ent object through call first activity.

public class SecondActivity extends ActionBarActivity {

private TextView tx1;

@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_second);

             tx1=(TextView)findViewById(R.id.textView1);
              Intent i=getIntent();
             String Fname=i.getStringExtra("Fname");
             String Lname=i.getStringExtra("Lname");

             tx1.setText("Your Name is: "+Fname+" "+Lname);
             Toast.makeText(getApplicationContext(), Fname+Lname, Toast.LENGTH_LONG).show();

            Button btn=(Button)findViewById(R.id.button1);

            btn.setOnClickListener(new OnClickListener() 
            {

                @Override
                public void onClick(View v) 
                {
                    // TODO Auto-generated method stub

                    //  Intent in=new Intent(SecondActivity.this,MainActivity.class);
                    //  startActivity(in);

                        Toast.makeText(getApplicationContext(), "Call First Activity",Toast.LENGTH_SHORT).show();
                }
            });

}

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

@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();
    if (id == R.id.action_settings)
    {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

}