// JavaScript Document
function displayScroller (mylayer, myscrollinglayer, myscroller) {
	// display scroller if the layer is too tall
	x=document.getElementById(mylayer);
	y=document.getElementById(myscrollinglayer);
	z=document.getElementById(myscroller);
	if(y.offsetHeight >x.offsetHeight){z.style.visibility='visible';}
}

function scrollHandler (myspeed, mylayer, myscrollinglayer, mydirection, action) {
	if	(action == 'start') {
			dmyspeed=myspeed; 
			dmylayer=mylayer;
			dmyscrollinglayer=myscrollinglayer;
			direction=mydirection; 
			scrollIntervalId = setInterval ( "scrollIt (dmyspeed,dmylayer, dmyscrollinglayer,direction)", 50 ); return scrollIntervalId;}
	else {clearInterval ( scrollIntervalId );}
}
var fast = 1;
function scrollIt (myspeed, mylayer, myscrollinglayer, direction) {
	var newTop;
	x=document.getElementById(mylayer);
	y=document.getElementById(myscrollinglayer);
	var papatop = x.offsetTop;
	var papaheight = x.offsetHeight;
	var intop = y.offsetTop;
	var inheight = y.offsetHeight;
	if(direction == "up") {
		newTop = (intop < 0)? intop+(myspeed*fast):intop;
		y.style.top = newTop + "px";
	}
	if (direction == "down") {
		newTop = ((inheight+intop) > papaheight)? intop-(myspeed*fast):intop;
		y.style.top = newTop + "px";
	}
}