function doFade() {
	if (document.getElementById('alertBox').style.visibility == 'hidden') {
		document.getElementById('alertBox').style.height = document.getElementById('silentPost').offsetTop+'px';
		document.getElementById('alertBox').style.opacity = 0.6;
		document.getElementById('alertBox').style.filter='alpha(opacity=60)';
		document.getElementById('alertBox').style.visibility = 'visible';	
	} else {
		document.getElementById('alertBox').style.visibility = 'hidden';
		document.getElementById('alertBox').style.height = '100%';
		document.getElementById('alertBox').style.opacity = 1;
		document.getElementById('alertBox').style.filter='alpha(opacity=100)';
	}
}