function setupMenu ( id ) {
	var menu = getElementById( id );
	var imgs = getChildrenByTagName( menu, 'img' );
	for ( var i = 0; i < imgs.length; i++ ) {
		if ( imgs[i].className == 'rollover' ) {
			imgs[i].onmouseover = changeImageOn_handler;
			imgs[i].onmouseout = changeImageOff_handler;
		}
	}
}
function changeImageOn_handler ( e ) {
	var img = getEventSource( e );
	if ( img ) {
		var imgOn = img.src.replace( '_off', '_on' );
		changeImage( img, imgOn );
	}
}
function changeImageOff_handler ( e ) {
	var img = getEventSource( e );
	if ( img ) {
		var imgOff = img.src.replace( '_on', '_off' );
		changeImage( img, imgOff );
	}
}
function changeImage ( imgElement, srcUrl ) {
	imgElement.src = srcUrl;
}