http://codestep.blogspot.com/2012/11/actionscript-30_12.html

 

https://www.youtube.com/watch?v=UHFkwfzcpSw&index=7&list=PLEcZ_OZzgI-qfcJp-fEAyQwaxPU9g_QWJ

 

http://www.zzzleepinclass.com/2013/08/Flash-ActionScript-3-Basic-PreLoader.html