var browser;
var layerRef, styleSwitch;
var jump = 18;
var miliwait = 20;
var scrolling = 0;

function browser_detect() {
  if(document.layers) browser="NS4";
  else if(document.all) browser="IE4";
  else if(document.getElementById) browser="DOM2";
  else browser="DOM2";
  if(browser=="NS4") {
    layerRef="document.layers";
    styleSwitch="";
  }
  if(browser=="IE4") {
    layerRef="document.all";
    styleSwitch=".style";
  }
  if(browser=="DOM2") {
    layerRef="document.getElementById";
    styleSwitch=".style";
  }
}

function showLayer(myLayer) {
  if(browser=="DOM2")
    eval(layerRef+'("'+myLayer+'")'+styleSwitch+'.visibility="visible"');
  else
    eval(layerRef+'["'+myLayer+'"]'+styleSwitch+'.visibility="visible"');
}

function hideLayer(myLayer) {
  if(browser=="DOM2")
    eval(layerRef+'("'+myLayer+'")'+styleSwitch+'.visibility="hidden"');
  else
    eval(layerRef+'["'+myLayer+'"]'+styleSwitch+'.visibility="hidden"');
}

function setTopLayer(myLayer,where) {
  if(browser=="DOM2")
    eval(layerRef+'("'+myLayer+'")'+styleSwitch+'.top='+where);
  else
    eval(layerRef+'["'+myLayer+'"]'+styleSwitch+'.top='+where);
}

function getTopLayer(myLayer) {
  if(browser=="NS4")
    return(eval(layerRef+'["'+myLayer+'"].pageY'));
  if(browser=="IE4")
    return(eval(layerRef+'["'+myLayer+'"].offsetTop'));
  if(browser=="DOM2")
    return(eval(layerRef+'("'+myLayer+'").offsetTop'));
}

function scrollDn(myLayer) {
	if(scrolling) {
		var count = getTopLayer(myLayer);
		if(count < 0) {
			if(count < (0 - jump)) { count += jump; }
			else { count = 0; }
			setTopLayer(myLayer, count);
		} else {
			scrolling = 0;
		}
		setTimeout('scrollDn("'+myLayer+'")', miliwait);
	}
}

function scrollUp(myLayer) {
	if(scrolling) {
		var count = getTopLayer(myLayer);
		if(count > -324) {
			count -= jump;
			setTopLayer(myLayer, count);
			scrolling = 1;
		} else {
			scrolling = 0;
		}
		setTimeout('scrollUp("'+myLayer+'")', miliwait);
	}
}

function scrollDown(myLayer) {
	scrolling = 1;
	scrollDn(myLayer);
}

function scrollBack(myLayer) {
	scrolling = 1;
	scrollUp(myLayer);
}

function scroll(myLayer) {
	var count = getTopLayer(myLayer);
	if(count <= -324) { scrollDown(myLayer); }
	if(count >= 0) { scrollBack(myLayer); }
}

function sliderStartup() {
  browser_detect();

  showLayer('slider');
  scrollDown('slider');
}