simple progress bar dialog in android with thread

below is the sample tutorial program to demonstrate a sample thread to display a progressbar in android.we just run the thread for a while and after that change the label to processing done we are using sleep here to emulate some useful operation just a add textview in the main.xml see the pic and below code increase the sleep value in case progress bar does not appear or closes too early to be viewed

public class ProgressDialogSample extends Activity implements Runnable {
private TextView txt;
private ProgressDialog progDailog;
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);

txt = (TextView) this.findViewById(R.id.main);
txt.setText("Press any key to start Process");
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

progDailog = ProgressDialog.show(curContxt,
"Progress dialogue sample ", "ceveni.com please wait....",
true);
new Thread() {
public void run() {
try{
// just doing some long operation
sleep(5000);
} catch (Exception e) { }
handler.sendEmptyMessage(0);
progDailog.dismiss(); }
}.start();
}//

private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
txt.setText("Processing Done");

}
};

}

we are using Handler because we get a across thread exception if we handle UI elements from other thread to overcome this problem we can post to the handler once the job / processing is completed so that UI thread can execute the ui operations once the processing gets on the thread gets completed.