ExternalInterface in flex?

I've only done a couple of .swf's, and that was with perl ming, which is great, but it has not really been maintained for a few years and predates ExternalInterface -- which I am not so interested in doing flash stuff unless there is a straightforward way of doing page/DOM (ie, javascript) interaction.

I got a few books on ActionScript and Flex from the library and have only glanced at them, but I notice that ExternalInterface is not in the index of either of them, and neither is javascript! So before I bother to get to work on this, install flex, etc, I am wondering: is ExternalInterface something Adobe kept out of flex, and you must pay the full $500 for CX or whatever to use it?

Is there another way to do javascript interaction? Basically is that something that is possible with flex, or not?

Looks like it's available.
http://learn.adobe.com/wiki/display/Fle ... +Interface

happy happy joy joy!