I am trying to make a call to user.login through this module. I am using the following POST string:

method="user.login"

This works, except that it says I haven't provided the sessid. I have the sessid to provide, but I cannot figure out how to pass it (and the username and password) to this module. No matter how I try to add arguments/args/params to the POST data, I get #invalid method. I have tried as many combinations as I can think of, and nothing works.

What should the format of the POST data be that will make this module happy?