Thanks for the great feedback all (lol @ jim)!
I'm not sure why I used a mouse up event instead of a mousedown (meaby habitual as I tend prefer mouseup on buttons so people can change their mind mid-click). All I can say is that I'm happy everything sort of works after after many sleepless nights. We had a really tight deadline (10 days) to get everything working. I did the programming, 2 others the graphics and another guy fixed the external php scripts for the automail and the FaceBook integration.
It was a first for me and off course technical difficulties enhanced the fun; my mail stopped working for the 1st time in history, had to switch mail mid project after I found out 4 days later, and my laptop couldn't open the source file in the last days (due to a corrupted PNG as I eventually found out).
I was really sweating it near the end (lot's of game-breaking bugs). Especially since I'm the guy that puts everything together, if I failed everybody did. It's good to look back on it though, it was worth it.