在adobe的网站上，有几种debug版本
http://www.adobe.com/support/flashplayer/downloads.html
第一个是IE的插件，
Download the Windows Flash Player 10.2 ActiveX control content debugger (for IE) (EXE, 2.99MB)
第二个是firefox的插件，
Download the Windows Flash Player 10.2 Plugin content debugger (for Netscape-compatible browsers) (EXE, 2.95MB)
安装了以上2个插件后，便可以用IE和firefox调试了。
第三个应该是桌面版本
Download the Windows Flash Player 10.2 Projector content debugger (EXE, 6.36MB)
到底是用IE还是firefox可以在window-> preference ->General->Web Browser 里选择合适的浏览。
我安装了chrome firefox ie，但选择里面没有chrome。但要用chrome来调试swf，也需要安装 for Netscape-compatible browsers 这个插件就行了。
C:/Program Files/Mozilla Firefox/plugins/NPSWF32.dll
Flash Builder cannot locate the required debugger version of Adobe Flash Player. You might need to install the debugger version of the Flash Player or reinstall Flash Builder.
Do you want to try to debug with the current version?
