Google Reader api mark all news from a specific source as read! I've the request

Google Reader api mark all news from a specific source as read! I've sniffed the request but I can't understant which paramters it want's

This is the post

http://www.google.com/reader/api/0/mark-all-as-read?client=scroll

and all arguments are

s=user%2F1400000000005773457%2Flabel%2FCultura&t=Cultura&ts=1302000000000000772&T=%2F%2FRcaqdpNe_mDnkehf-L5af9w

NOTE: The Numeber like 14000000000057734... are not true...I masquerade it because I think they are sensible data.

My questions is can someone show me the correct request? Which are the correct parameters to do this post request?

The request that I show in this post works because I grab It from the Google Reader site.

The relevant parameters are:

1. s: The stream you wish to mark all as read. The example you have is marking as read the user's "Cultura" label. To mark a feed you you use feed/<feed url>
2. ts: The timestamp (in microseconds) you wish to mark all as items as read to. This can be the current time (to mark all items), or a date in the past (e.g. to mark all items older than 1 week as read, use the current time minus 1 weeek.
3. T: The action token (necessary for all POST requests)