knowing scroll position of frame

[dp_goose]

I have a scrollable frame (used for a tree style menu) that doesn't show a scroll bar. When the mouse moves over certain other frames/objects I kick off an event that scrolls the frame using scrollBy. This bit works fine.

Due to the layout I want to add some up and down arrows but only show them when there is something to scroll to. How can I get the length of the frame and the current scroll position?

I can only use javascript and html. Must be no vb/flash etc.

Thanks

Goose