var state = new Array(4);
var alpha = new Array(4);
var layer = new Array(4);

function init()
{
	layer[0] = 'empresa';
	layer[1] = 'situacion';
	layer[2] = 'indumentaria';
	layer[3] = 'contacto';
	
	for (var t = 0; t < 4; t ++)
	{
		state[t] = 0;
		alpha[t] = 0;
		changeOpac(0, layer[t]);
		document.getElementById(layer[t]).style.visibility = 'visible';
	}
	
	int = setInterval("step()", 50);
}

function changeOpac(opacity, id)
{
	var object = document.getElementById(id).style; 
	object.opacity = (opacity / 100);
	object.MozOpacity = (opacity / 100);
	object.KhtmlOpacity = (opacity / 100);
	object.filter = "alpha(opacity="+opacity+");";
}

function alphaFilter(id,st)
{
	state[id] = st;
}

function step()
{
	for (var t = 0; t < 4; t ++)
	{
		if (state[t] == 1)
		{
			alpha[t] += 10;
			if (alpha[t] >= 100) state[t] = 0;
			changeOpac(alpha[t], layer[t]);
		}
		else if (state[t] == 2)
		{
			alpha[t] -= 10;
			if (alpha[t] <= 0) state[t] = 0;
			changeOpac(alpha[t], layer[t]);
		}
	}
}