Unleashed falling Snow HELP

Hi there,
I successfully went through the falling snow tutorial and i managed to change it into a flowerrain with different type of flowers.

I have built an Intromovie for my site and i want this flowerrain to be playing on top of it in a smaller size than the mainframe (1024x768).
I managed to do that also but the Flowereffekt always sticks to the upper left corner and I WANT IT CENTERED!!!
Tried a couple of things already but i am pretty new to this programm nothing wont work.
I am assuming that i have to put some extra lines in the actionscript where the size of the effekt ist defined but i dont know what!!!

I thankful for any kind of help!!!