Download String From Address "http://www.last.fm/music/Boney%20M./+images"

Download String From Address "http://www.last.fm/music/Boney%20M./+images"

I`m trying to download string from address
"http://www.last.fm/music/Boney%20M./+images",but return null,
WebClient webClient = new WebClient();
string html = webClient.DownloadString(new
Uri("http://www.last.fm/music/Boney%20M./+images"));