About accessing data in loaded SWF files

One SWF file can load another SWF file from any location on the Internet. However, for one SWF file to access data (variables, methods, and so forth) defined in the other SWF file, the two files must originate from the same domain. In Flash Player 7 and later, cross-domain scripting is prohibited unless the loaded SWF file specifies otherwise by calling System.security.allowDomain().

For more information, see System.security.allowDomain() and Flash Player security features.