Flash CS3 big problem for AS2 developers

Hi All,

Can anybody tell me what is new in Flash CS3?

I was working on Flash from last 5-6 years, and I am stuck with Flash new version.
I don’t know, why a lot of my code is not working on AS3, even I cannot write simple onRelease(), onRollOver() functions in CS3 environment.

Any suggestions would be appreciated for right guidance.