var dom = document.getElementById;
var iex = document.all;
var ns4 = document.layers;

function addEvent(event,method){
	this[event] = method;
	if(ns4) this.captureEvents(Event[event.substr(2,event.length).toUpperCase()]);
}
function removeEvent(event){
	this[event] = null;
	if(ns4) this.releaseEvents(Event[event.substr(2,event.length).toUpperCase()]);
}
function getElement(name,nest){
	nest = nest ? 'document.'+nest+'.' : '';
	var el = dom ? document.getElementById(name) : iex ? document.all[name] : ns4 ? eval(nest+'document.'+name) : false;
	el.css = ns4 ? el : el.style;
	el.hideVis = function(){el.css.visibility='hidden'};
	el.showVis = function(){el.css.visibility='visible'};
	el.getTop = function(){return parseInt(el.css.top) || 0};
	el.setTop = function(y){el.css.top=y};
	el.getHeight = function(){return ns4 ? el.document.height : el.offsetHeight};
	el.getClipHeight = function(){return ns4 ? el.clip.height : el.offsetHeight};
	el.addEvent = addEvent;
	el.removeEvent = removeEvent;
	return el;
}
function getMouse(e){
	return iex ? event.clientY : e.pageY;
}

document.addEvent = addEvent;
document.removeEvent = removeEvent;

function newImage(src){
	img = new Image();
	img.src = src;
	return img;
}
function imageSwap(img,obj,div){
	obj = eval(obj);
	if(document.layers && div != null){
		document.layers[div].document.images[img].src = obj.src;
	}else{
		document.images[img].src = obj.src;
	}
}
function fixNetscape(){
	if(ns4origWidth != window.innerWidth || ns4origHeight != window.innerHeight){
		window.location.reload();
	}	
}
if(document.layers){
	ns4origWidth = window.innerWidth;
	ns4origHeight = window.innerHeight;
	window.onresize = fixNetscape;
}

var currentContent = null;

var upOff = newImage('sajtgifs/scroll_images/scr_up.gif');
var upOn = newImage('sajtgifs/scroll_images/scr_up_on.gif');
var dwOff = newImage('sajtgifs/scroll_images/scr_dw.gif');
var dwOn = newImage('sajtgifs/scroll_images/scr_dw_on.gif');
var aboOff = newImage('sajtgifs/scroll_images/nav_off.gif');
var aboOn = newImage('sajtgifs/scroll_images/nav_on.gif');


function initScroller(){
	scrollSpeed = 4;
	dragHeight = 9;
	trackHeight = 335;
	trackObj = getElement('tr');
	upObj = getElement('up');
	downObj = getElement('dw');
	dragObj = getElement('dr');
	contentMaskObj = getElement('contentMask');
	trackTop = dragObj.getTop();
	trackLength = trackHeight-dragHeight;
	trackBottom = trackTop+trackLength;
	contentMaskHeight = contentMaskObj.getClipHeight();
	scrollTimer = null;
	
	trackObj.addEvent('onmousedown',scrollJump);
	
	upObj.addEvent('onmousedown', function(){scroll(scrollSpeed);return false});
	upObj.addEvent('onmouseup', stopScroll);
	upObj.addEvent('onmouseout', stopScroll);
	
	downObj.addEvent('onmousedown', function(){scroll(-scrollSpeed);return false});
	downObj.addEvent('onmouseup', stopScroll);
	downObj.addEvent('onmouseout', stopScroll);
	
	dragObj.addEvent('onmousedown', startDrag);
	dragObj.addEvent('ondragstart', function(){return false});
	
	docLoaded = true;
	loadContent('abo');
}
function loadContent(name){
	if(!docLoaded) return;
	if(currentContent!=null){
		imageSwap(currentContent, currentContent+'Off', 'nav');
		contentObj.setTop(0);
		contentObj.hideVis();
	}
	currentContent = name;
	imageSwap(name, name+'On', 'nav');
	contentObj = getElement(currentContent+'Content','contentMask');
	contentHeight = contentObj.getHeight();
	contentLength = contentHeight-contentMaskHeight;
	scrollLength = trackLength/contentLength;
	contentObj.showVis();
	dragObj.setTop(trackTop);
	if(contentHeight<=contentMaskHeight){
		trackObj.hideVis();
		upObj.hideVis();
		downObj.hideVis();
		dragObj.hideVis();
	}else{
		trackObj.showVis();
		upObj.showVis();
		downObj.showVis();
		dragObj.showVis();
	}
}
function startDrag(e){
	dragStartMouse = getMouse(e);
	dragStartOffset = dragObj.getTop();
	document.addEvent('onmousemove', drag);
	document.addEvent('onmouseup', stopDrag);
	return false;
}
function stopDrag(){
	document.removeEvent('onmousemove');
	document.removeEvent('onmouseup');
}
function drag(e){
	var currentMouse = getMouse(e);
	var mouseDifference = currentMouse-dragStartMouse;
	var dragDistance = dragStartOffset+mouseDifference;
	var dragMovement = (dragDistance<trackTop) ? trackTop : (dragDistance>trackBottom) ? trackBottom : dragDistance;
	dragObj.setTop(dragMovement);
	var contentMovement = -(dragMovement-trackTop)*(1/scrollLength);
	contentObj.setTop(contentMovement);
	return false;
}
function scroll(speed){
	var contentMovement = contentObj.getTop()+speed;
	var dragMovement = trackTop-Math.round(contentObj.getTop()*(trackLength/contentLength));
	if(contentMovement > 0){
		contentMovement = 0;
	}else if(contentMovement < -contentLength){
		contentMovement = -contentLength;
	}
	if(dragMovement < trackTop){
		dragMovement = trackTop;
	}else if(dragMovement > trackBottom){
		dragMovement = trackBottom;
	}
	contentObj.setTop(contentMovement);
	dragObj.setTop(dragMovement);
	scrollTimer = window.setTimeout('scroll('+speed+')',25);
}
function stopScroll(){
	if(scrollTimer){
		window.clearTimeout(scrollTimer);
		scrollTimer = null;
	}
}
function scrollJump(e){
	var currentMouse = getMouse(e)-document.body.clientHeight/2-60;
	var dragDistance = currentMouse-(dragHeight/2);
	var dragMovement = (dragDistance<trackTop) ? trackTop : (dragDistance>trackBottom) ? trackBottom : dragDistance;
	dragObj.setTop(dragMovement);
	var contentMovement = -(dragMovement-trackTop)*(1/scrollLength);
	contentObj.setTop(contentMovement);
	return false;
}
function hideOverflow(){
	var agent = navigator.userAgent.toLowerCase(); 
	if(agent.indexOf('mac') != -1 && document.all){
		document.body.scroll = 'no';
	}
}
function setimg(name,activate)
{
  var obj;
  var indx;
  indx = name.indexOf(".");
  if (indx > 0 )
    obj = name.substring(0,indx);
  else
    obj = name;
  if (activate)
  {
    document[name].src = eval(obj + "On" + ".src");
  }
  else
  {
    document[name].src = eval(obj + "Off" + ".src");
  }
}