MACROMEDIA FLASH 8-ACTIONSCRIPT 2.0 LANGUAGE Reference page 550

ExternalInterface is supported in the following combinations of browser and operating
system:
Browser
Internet Explorer 5.0
and higher
Netscape 8.0 and
higher
Mozilla 1.7.5 and
higher
Firefox 1.0 and higher
Safari 1.3 and higher
ExternalInterface requires the user's web browser to support either ActiveX or the
NPRuntime API that is exposed by some browsers for plugin scripting. See http://
www.mozilla.org/projects/plugins/npruntime.html.
Availability: ActionScript 1.0; Flash Player 8
Property summary
Modifiers Property
static available:Boolean
[read-only]
Properties inherited from class Object
constructor (Object.constructor
property), prototype (Object.prototype
(Object.__resolve property)
550 ActionScript classes
Operating System
Windows
Windows
Windows
Windows
Description
Indicates whether this player is in a container that
offers an external interface.
property),
Macintosh
Macintosh
Macintosh
Macintosh
__proto__ (Object.__proto__
property), __resolve