Resource cost : get more paid !

Hi

I am trying to check if I can follow my project cost with this wonderful tool.
I set a cost to my resource.
Now I would like to give him an higher salary
So let say the first cost is 100 euro per day, and from 2011/11/01 the cost will be 150.

I wonder if I can do that. There is a "start date" in the "resource cost" form, but the role of this entry is not clear to me.
Moreover, this entry is disabled.

Is this possible to change the cost of a resource from a given date, and if so, how may I do it ?

Best regards
Sky

Hi
Thanks. I had check in [url]http://127.0.0.1/projectorria/manual/manual.php[/url] before asking but was unable to find the answer.
(I use projectorria V1.7.2). Is it in the activity section ?

(F1 goes to support.mozilla.com/fr/home?as=u on firefox )
Best regards
Sky

Hi
Lastest documentation found at projectorria.toolware.fr/manual/manual.php
Clearly more detailed than mine.
Forget my request, it is obsolete.
Best regards
Sky