This 30 minute talk by MFP explains how you can customize the business logic in Dynamics AX 4.0, in a way that makes future code upgrades easier.
Click here for the link
This site contains some Microsoft Dynamics AX X++ Codes for use in your day to day use. However please use them with caution in production environment. I will not be responsible for any Goof ups. These Codes were created during my free time and may have bugs. Use them at your own discretion. Arijit Basu | India