var current_timeout;
var dir; //direcao

function start_animation(mov)
{
	current_timeout = setTimeout("anime()",50);
	dir = Math.round(mov);
}

function animation(mov)
{
	dir = Math.round(mov);
	anime();
}

function anime()
{
	var move = true;
	var v = document.getElementById("box_principal_produtos");
	var left_ = parseInt(v.style.left);
	var diminuir = '', aumentar='';
	if(dir>0 && left_ >= 0)
	{
		move = false;
		v.style.left = '0px';
		aumentar = 'opacity';
	}
	
	if(dir<0 && left_ <= (box_width - box_vitrine)*-1)
	{
		move = false;
		v.style.left = ((box_width - box_vitrine)*-1)+'px';
		diminuir = 'opacity';
	}

	document.getElementById("aumentar").className = aumentar;
	document.getElementById("diminuir").className = diminuir;
	
	if(move)
	{
		v.style.left = (left_ + dir) + 'px';
		current_timeout = setTimeout("anime()",50);
	}
}

function stop_animation()
{
	clearTimeout(current_timeout);
}