function fadeIn(eid, timeToFade)
{
	var element = document.getElementById(eid);
	if(element == null)
		return;

	if(element.style.opacity != 0.0)
		return
	
	element.style.visibility = "visible";
		
	fadeStep(eid,1,timeToFade/10,0);
}

function fadeOut(eid, timeToFade)
{
	var element = document.getElementById(eid);
	if(element == null)
		return;
	
	if(element.style.opacity != 1.0)
		return

	fadeStep(eid,-1,timeToFade/10,10);

}


function fadeStep(eid, step, stepLength, currentOpacity)
// executa fade-in ou fade-out de um elemento no tempo (stepLength/step).
// step deve ser -10 < step < 10; step também deve ser != 0;
// A.P.

{
	if ((step < -10) || (step > 10) || (step == 0)) 
		return;
		
	var element = document.getElementById(eid);
	if(element == null)
		return;
	
	if (step > 0) 
	{	
		if (currentOpacity < 10)
		{
			currentOpacity += step;
			element.style.opacity = currentOpacity / 10;
			setTimeout("fadeStep('" + eid + "'," + step + "," + stepLength + "," + currentOpacity + ")", stepLength);
		}
		else		
		{
			element.style.opacity = 1.0;
		}		
	}
	else
	{
		if (currentOpacity > 0)
		{
			currentOpacity += step;
			element.style.opacity = currentOpacity / 10;
			setTimeout("fadeStep('" + eid + "'," + step + "," + stepLength + "," + currentOpacity + ")", stepLength);
		}
		else		
		{
			element.style.opacity = 0.0;
		}
	}
}



function pausecomp(ms) {
	ms += new Date().getTime();
	while (new Date() < ms){}
}