[TYPO3-project-seminars] Where does the URL in the registration form come from?

[Jens Cramer]

Hello there,
I want to use a SSL-Connection for the registration process. The TS-Variable
plugin.tx_seminars_pi1.baseURL is already modified to a https-URL.
When I start the registration everythinks seems to be ok. If I try to switch
from the registration step 1 to step 2 I loose my php session, because the
form has the action-tag http://mydomain.de/... and not
https://www.mydomain.de/....

Do you know, where the http-URL comes from? Thanks!

Greets
Jens Cramer