Iframe Javacript Scrolling

[Klaus]

Hi!
I have an Iframe in a html-page that can be scrolled via two buttons (two *.gif graphics). Everything works perfect. My only problem is: Is it possible to show the scroll-buttons only if they are really neccasary? Neccasary means: only visible when the content of the page loaded in the Iframe is too large for the Iframe. Because it's somehow confusing seeing the curser-hand over the scroller but nothing is moving...

Here is the link to the site with the Iframe(s):

http://bergrettung-axams.at/potsdamer/willkommen.html

(The Site is made mainly for IE)

THANK YOU, Klaus