Check RSS Feed and update my app.

I am new to this software and android development.

I am useing this code example from this site.
http://www.b4x.com/forum/basic4android-updates-questions/15382-rss-feed.html

I want to check the rss feed and show update notification and of course load up the xml file again in the list view.

I have been studying the notification part .

I need help with how to check the xml feed to see if something new is added.

Thanks for your advice.