[flexcoders] External Interface: Do I have to have a javascript function?

[thegators_2002]

When I call from a Flex swf to the host aspx page, do I have to have a
javascript function that will answer?  Can I directly access a hidden
field on the page from Flex?

I would like to do something like this:

ExternalInterface.call("window.document.getElementById('hidBVPerm').value");

But the aspx page thinks that is the name of a function I am passing.
 I want to know if there is a way I can just get the value of that
hidden field without having to write a javascript function?

Thanks,
Pete