var fading = false;
var fadeTime = 2500;

function fadeOut()
{
	$('#pca').animate({ opacity: 0.0 }, fadeTime);
}

function okToFade()
{
	fading = false;
}

$(window).scroll(function () {
	if(fading == false)
	{
	  fading = true;	  
	  $('#pca').animate({ opacity: 0.03 }, 0);
	  setTimeout("okToFade()",fadeTime+100);
	  fadeOut();
	}	
});