AS3: Opening a window in the users browser

Use navigateToURL if you want to open a window in the users browser. For example:

 navigateToURL(new URLRequest("http://www.lazysquirrelgames.com"),  
  "_blank"); 

Adobe documentation:
http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/net/URLRequest.html