var speed = 25;				// scrollozas sebessege (nagyobb = gyorsabb)
var dir_down = false;		// lefele scrollozodik-e a DIV
var step = 1;				// lepeskoz (egyszerre ennyi keppontot mozdul a DIV)
var scroller_height = 0 	// A kulso elem magassaga, amiben belul a scrollozodo DIV van (pixelben, de csak a szam kell)


// Objektum szelessegenek lekerdezese.
//
function objWidth(obj)
{
	if (obj.offsetWidth) {return obj.offsetWidth;}
	else if (obj.clip) {return obj.clip.width;}
	else {return 0;}
}


// Objektum magassaganak lekerdezese.
//
function objHeight(obj)
{
	if (obj.offsetHeight) {return obj.offsetHeight;}
	else if (obj.clip) {return obj.clip.height;}
	else {return 0;}
}


// Scrollozas tenyleges vegrehajtasa.
//
function scrF(obj, sH, eH)
{
	var x = parseInt(obj.top) + (dir_down ? step : -step);
	if (dir_down && x>(sH-scroller_height)) {dir_down = false;}
	else if (x < 2-(eH-scroller_height)) {dir_down = true;}
	obj.top = x + 'px';
}


// Scrollozando tartalom felepitese es elokeszitese a scrollozasra.
//
// obj_id: a scrollozando DIV id-je.
// content: az elobbi DIV-ben megjelenitendo es scrollozando tartalom.
//
function startScroll(obj_id, content)
{
	var scr = document.getElementById(obj_id);
	var sW = objWidth(scr) - 6;
	var sH = objHeight(scr);
	scr.innerHTML = '<div id="'+obj_id+'in" style="position:absolute; left:3px; width:'+sW+'; background-color: inherit; color: inherit;">'+content+'<\/div>';
	var sTxt = document.getElementById(obj_id+'in');
	var eH = objHeight(sTxt);
	sTxt.style.top = (dir_down ? -eH : (sH-scroller_height))+'px';
	sTxt.style.clip = 'rect(0,'+sW+'px,'+eH+'px,0)';
	setInterval(function() {scrF(sTxt.style,sH,eH);},1000/speed);
}


// Scroller hozzaadasa egy DIV-hez.
//
// obj_id: a scrollozando DIV id-je.
// content: az elobbi DIV-ben megjelenitendo es scrollozando tartalom.
// obj_height: az elem magassaga, amiben a scrollozando DIV van (pixelben, csak a szam)
//
function addScrollers(obj_id, content, obj_height) {
	scroller_height = obj_height+5;
	startScroll(obj_id, content);
}