I installed the app but can't figure out how to send an sms.

First, I entered the account information via the "Account Setup" menu. Tehre I filled the fields for "Login" and "password" and chose my provider (o2 Germany) However, the dropdown menu "account" does not list any options. Neither can I enter anything under account.

Saving and returning to the sms form, I enter a cell number and text. But the "send" button is still dark and i can't press it. When I do that, I am having an active 3G connection to o2. Why is the send button darkly shaded and what do I have to do in order to be able to send messages?

Thx for any comments!