Stop the Music in WebView when Screen Time-Out

Question

I am programming that allow users can listen music in WebView via the URL web link. But I wonder why when the android phone user screen Time-Out my music in WebView also stop. Do you have any solution to solve this problem?

Here is my code:

public class PlayMusicActivity extends Activity {

WebView mWebView;
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.playlist);

    mWebView = (WebView) findViewById(R.id.webView1);
    mWebView.setWebViewClient(new HelloWebViewClient());
    mWebView.getSettings().setJavaScriptEnabled(true);
    mWebView.getSettings().setPluginsEnabled(true);
    mWebView.getSettings().setAllowFileAccess(true);
    mWebView.loadUrl("http://www.myweb.com/music.html");
}
private class HelloWebViewClient extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        view.loadUrl(url);
        return true;
    }
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if ((keyCode == KeyEvent.KEYCODE_BACK) && mWebView.canGoBack()) {
        mWebView.goBack();
        return true;
    }
    return super.onKeyDown(keyCode, event);
}
@Override
public void onPause() {
    mWebView.setVisibility(View.GONE);
    mWebView.destroy();
    super.onPause();
}
}

Appreciate for your help.

Best regards, Virak