Handling RSS Tags with NSXMLParser for iPhone

I've found the following code for parsing through RSS but it does not seem to allow for nested elements:

- (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{         NSLog(@"ended element: %@", elementName);    if ([elementName isEqualToString:@"item"]) {        // save values to an item, then store that item into the array...        [item setObject:currentTitle forKey:@"title"];        [item setObject:currentLink forKey:@"link"];        [item setObject:currentSummary forKey:@"summary"];        [item setObject:currentDate forKey:@"date"];        [item setObject:currentImage forKey:@"media:thumbnail"];

The RSS to used is:

<item><title>Knife robberies and burglaries up</title><description>The number of robberies carried out at knife-point has increased sharply and burglaries are also up, latest crime figures indicate</description><link>http://news.bbc.co.uk/go/rss/-/1/hi/uk/7844455.stm</link><guid isPermaLink="false">http://news.bbc.co.uk/1/hi/uk/7844455.stm</guid><pubDate>Thu, 22 Jan 2009 13:02:03 GMT</pubDate><category>UK</category><media:thumbnail width="66" height="49" url="http://newsimg.bbc.co.uk/media/images/45400000/jpg/_45400861_policegeneric_pa.jpg"/></item>

I need to extract the "url" element from the "media" tag.

ThanksMartin