threading Example in android

package test12.tt;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class Test12Activity extends Activity {

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        final TextView txt1 = (TextView) findViewById(R.id.sm);

        new Thread(new Runnable() {
            public void run(){

        txt1.setText("Thread!!");


            }
    }).start();

    }

}


And the Android XML

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView 
android:id = "@+id/sm"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello"
    />
</LinearLayout>