because that is completely improper object oriented programming.
There should be no need for _global variables/functions. But why it's failing is because a class definition only holds variables/functions local to that class. Hence a "class definition". If you must define that _global function, do it inside of the constructor or inside of another method.
Please excuse my ignorance, but if the class definition only holds variables/functions local to that class, then how is the code supposed to look? I have attached two ".as" files, the first one "LoaderListener.as" is the file with the code that I pasted above and the second one "MCListener.as" is the only file that directly refers to the "LoaderListener.as" file. If you could let me know what the code should be for the code I pasted above, that would help me out big time.