recording rtmp streaming with quality change

[luke88]

Hi, i'm trying to download a video from here for personal copy:
http://www.foxtv.it/the-walking-dead/web-episode (you have to register to be able to see it)
they use flash video and rtmp stream, i successfully downloaded the default video, but they let you choose the quality of the video directly from the flash video player, so if i use your program it will always download the first and default stream.
Is there a way to get the better stream in some way?
Thanks in advance