Flash has some features to make coding easier. Some of the features include code collapse, code hinting, and commenting buttons. One of the other features is auto format which is extremely satisfying if your copy and pasting and your tabbing gets crazy.
If your code has no syntax errors auto format will indent it properly, add spaces and put your curly braces where you would like them to be. For even more control over auto format, you can change how it auto formats under preferences. Go to Flash > Preferences > Auto Format. There you can check off the auto format behaviors that best suit you.
There is one caveat to using auto format that could drive you to near madness if you can not prepared for it’s evil. It could add a line termination “;” to the class definition line. I’ve had it happen several times and I don’t know what makes it happen. I was unable to replicate it in a test. If it happens it will give you a 1084 error code in the Compiler window. It’s easily resolved, but it happened more than a few times to me, so I’d rather just be careful and use the tab key.