var tt_VSCROLL={
timerId: '',
s: 1,
scroll: function(id,scrollerPostfix,cssPostfix,s)
{
	this.s=s;
	var obj=document.getElementById(id);
	var upObj=document.getElementById('vscrUp'+scrollerPostfix);
	var downObj=document.getElementById('vscrDown'+scrollerPostfix);
	obj.scrollTop=obj.scrollTop+this.s;
	//fent van
	if(obj.scrollTop===0)
	{
		clearTimeout(tt_VSCROLL.timerId);
		upObj.className='vscrUpOff'+cssPostfix;
		downObj.className='vscrDown'+cssPostfix;
		return;
	}
	//lent van
	else if(obj.scrollTop===obj.scrollHeight-parseInt(obj.style.height,10))
	{
		clearTimeout(tt_VSCROLL.timerId);
		upObj.className='vscrUp'+cssPostfix;
		downObj.className='vscrDownOff'+cssPostfix;
		return;
	}
	//középen
	else
	{
		upObj.className='vscrUp'+cssPostfix;
		downObj.className='vscrDown'+cssPostfix;
	}
	tt_VSCROLL.timerId=setTimeout(function(){
	tt_VSCROLL.scroll(id,scrollerPostfix,cssPostfix,tt_VSCROLL.s);
	},10);
}
};