var speed = 5; // Scroll speed
var xTop = 0;
var xBottom = 220;

var posx = 0;
var posy = 0;
var active_scroller = false;
function setMouseXY(e)
{
	if (!e) var e = window.event;
	if (e.pageX || e.pageY)
	{
		posx = e.pageX;
		posy = e.pageY;
	}
	else if (e.clientX || e.clientY)
	{
		posx = e.clientX + document.documentElement.scrollLeft;
		posy = e.clientY + document.documentElement.scrollTop;	
		
	}	
	if(active_scroller == false)
	{
		active_scroller = true;
		calculateSpeed(posx,posy);
		scrollIt(posx,posy);
	}
	else
	{
		//nastav offest
		calculateSpeed(posx,posy);
		/*if(!( (posx>0 && posx<292) && (posy>258 && posy<478)))
		{
			up();	
		}*/
	}
}

function scrollIt(x,y)
{
	
	var offset = (document.body.clientWidth - 900) / 2;
	x = x - offset;
	if( (x>0 && x<292) && (y>258 && y<358) && active_scroller )
	{
		scrollUp();
	}
	else if( (x>0 && x<292) && (y>378 && y<478) && active_scroller )
	{
		
		scrollDown();
	}
	else
	{
		//document.getElementById('div_content').style.backgroundColor='#fff';
		up();
	}
}
function calculateSpeed(x,y)
{
	var offset = (document.body.clientWidth - 900) / 2;
	x = x - offset;
	if( (x>0 && x<292) && (y>258 && y<358) && active_scroller )
	{
		speed = parseInt(((359 - y) / 100) * 7);
		//speed=1;
	}
	else if( (x>0 && x<292) && (y>378 && y<478) && active_scroller )
	{
		speed = parseInt(((377 - y) / 100) * 7);
		//speed=-1;
	}
	else
	{
		up();	
	}
}


function init(id)
{
	// Set-up to use getMouseXY function onMouseMove
	document.onmousemove = setMouseXY;
	
	if(ie4){
		contentH = parseInt(document.all.div_content.scrollHeight);
		contentClipH = parseInt(document.all.contentClip.style.height);
    	//document.all.drag.style.height=55;
	}
	else if(nn4){
		contentH = document.contentClip.document.div_content.clip.bottom;
		contentClipH = document.contentClip.clip.bottom;
	}
	else if(dom){
		contentH = parseInt(document.getElementById("div_content").offsetHeight);
		contentClipH = parseInt(document.getElementById("contentClip").offsetHeight);
	}
  getT();

  moveTo();
	// Number of pixels scrollbar should move
	scrollLength = ((xBottom-xTop)/(contentH-contentClipH));

}




// Browser detection
var opera = false;
if (navigator.appName.toLowerCase() == "opera" && navigator.appVersion.substring(0,1) <= 6) {
  opera = true; // this will detect opera (but only in some cases ...)
}
var dom = document.getElementById ? true:false;
var nn4 = document.layers ? true:false;
var ie4 = document.all ? true:false;


var timer = setTimeout("",500); // Repeat variable
var dragT=xTop; // Scrollbar Y
var contentT; // Content layer Y;
var contentH; // Content height
var contentClipH; // Content clip height
var scrollLength; // Number of pixels scrollbar should move
var startY; // Keeps track of offset between mouse and span


function up(){	
	active_scroller = false;
	clearTimeout(timer);
	// Resetting variables
	clickUp = false;
	clickDown = false;
	clickDrag = false;
  	onDrag=false;
	speed = 1;
 	
 	 return true;
}
function nocontextmenu() {
  event.cancelBubble = true, event.returnValue = false;

  return false;
} 

// Reads content layer top
function getT(){
	if(ie4)
		contentT = document.all.div_content.style.pixelTop;
	else if(nn4)
		contentT = document.contentClip.document.div_content.top;
	else if(dom)
		contentT = parseInt(document.getElementById("div_content").style.top);
}

// Moves the layer
function moveTo(){
	
	if(ie4){
		document.all.div_content.style.top = contentT;
	}
	else if(nn4){
		document.contentClip.document.div_content.top = contentT;
	}
	else if(dom){
		document.getElementById("div_content").style.top = contentT + "px";
	}
}

// Scrolls up
function scrollUp(){
	getT();
	
		if(contentT < 0){		
			contentT = contentT + speed;
			if(contentT > 0)
				contentT = 0;
			if(contentT < -(contentH - contentClipH))
				contentT = -(contentH - contentClipH);
				
			//document.getElementById("vypis").innerHTML = "up";
			moveTo();
			timer = setTimeout("scrollUp()",10);
		}
		else
		{
			active_scroller = false;
			clearTimeout(timer);	
		}
	
	return false;
}

// Scrolls down
function scrollDown(){
	getT();
	
		if(contentT > -(contentH - contentClipH)){			
			
			
			contentT = contentT + speed;
			if(contentT > 0)
				contentT = 0;
			if(contentT < -(contentH - contentClipH))
				contentT = -(contentH - contentClipH);
			
			//document.getElementById("vypis").innerHTML = "down";
			moveTo();
			timer = setTimeout("scrollDown()",10);
		}
		else
		{
			active_scroller = false;
			clearTimeout(timer);	
		}
	
	return false;
}

// reloads page to position the layers again
function reloadPage(){
	location.reload();
}