Its been a while since i write something into my blog, but I want to share my experience over this topic.
As you develop project for sometime one Flash, and your code get bigger and bigger:

Source Code Statistics:

Code lines: 54 937 (59%)
Comment lines: 20 347 (21,9%)
Blank lines: 17 847 (19,2%)

Total lines: 93 121

You will reach in some point where Flash is not able to compile your project. It just throws flash with no action script at all or blank scene.
Thanks to this topic: Giving Flash CS3′s compiler a little breathing room, I manage to overcome this problem.

I will write the steps in win7, because I use this OS.

• Right click on Computer
• Choose properties
• Choose Advanced system settings
• Choose Advanced tab
• Environment Variables…
• Click on New to add variable
• Variable name: JAVA_TOOL_OPTIONS and for variable value add -Xmx@M, where @ is the size you want your Java virtual machine to use, it can be 256, 512, 1024 (Example : -Xmx512M or -Xmx256M)

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