Auto-completion is nice. The less typing done, the less chance of bugs.
Use these paths to point to Adobe's code, so Flash Develop knows where to look.
Ctrl + F9 to open up Global Paths.
Choose AS3 in the drop down menu.
Copy and paste away.
C:\Program Files\Adobe\Adobe Flash CS3\en\Configuration\Component Source\ActionScript 3.0\User Interface\
C:\Program Files\Adobe\Adobe Flash CS3\en\Configuration\ActionScript 3.0\Classes
C:\Program Files\Adobe\Adobe Flash CS3\en\First Run\Classes
