Communicating with javascript into an iframe????

[Simon Wigzell]

I have a site where I am using an iframe to load different pages depending
which button is pressed:

http://www.pheenomenum.com/Example.htm

I have the content within the iframe self scrolling. There is some control
over this with the mouse - mouse out to make it start, mouse in to make it
stop, double click to make it reverse direction.

I would rather have these controls though as buttons in the main window
along with some additional features like go to end/beginning, jump one
screen down/up.

Is there any way that my javascript in the main window can call javascript
functions in the iframe window?

Thanks!