1. Add a new mxml application into one existed app and named it as what you want. Mine is TestApp.mxml.

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2. Use the right key of your mouse to click your application listed in Flex Navigator, then open the Properties for yourappname dialog.

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3. Select Flex Modules panel, “add” TestApp.mxml as a module. Do not “browse” to add TestApp.xml, you can not find it in the Select Module dialog, just edit the Source path like this “src/TestApp.mxml”. Pay attention here : you should select “Do not optimize (module can be loaded by multiple applications)” instead of the default option in order to generate a standalone SWF file.

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4.Compile your application using Build Project or Builder All as you wish. Then you can find two, or more if any, SWF files displayed in bin-debug directory.

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