Few basic questions on flex/AS

Guys i have struggling with flex since a day or two.I havent found a nice short tutorials.Actually i also have been struggling with FLEX IDE too.Please indicate a nice good tutorials for this I basically have questions like

• Cannot use Alert in AS
• Including a AS file in mxml file
• org.com.structure and the as fi开发者_如何学Gole in it.Why do we need to say pacakage org.com inside the as file

• You can use flex Alert class. In pure AS, unlike JavaScript, there is no alert().
• <mx:Script source="script.as"/>. But script.as will not know about MXML file, it's better to use class defined in as file as a control in MXML.
• Because packages are compiler-enforced design decision, and who we are to discuss it.

Flex in a week!

http://www.adobe.com/devnet/flex/videotraining.html

This video series helped me a lot..