// Opacity and Fade in script.
// Script copyright (C) 2008 http://www.cryer.co.uk/.  
// http://www.cryer.co.uk/resources/javascript/script19_fade_image.htm
// Script is free to use provided this copyright header is included.
function SetOpacity(object, opacityPct)
{
	if(object==null)	return;
	// IE.
	object.style.filter = 'alpha(opacity=' + opacityPct + ')';
	// Old mozilla and firefox
	object.style.MozOpacity = opacityPct/100;
	// Everything else.
	object.style.opacity = opacityPct/100;
}

function ChangeOpacity(id,msDuration,msStart,fromO,toO)
{
	var element=document.getElementById(id);
	if(element==null)	return;				//added by Fung 2010-11-1
	var opacity = element.style.opacity * 100;
	var msNow = (new Date()).getTime();
	opacity = fromO + (toO - fromO) * (msNow - msStart) / msDuration;
	if(opacity<0)			SetOpacity(element,0)
	else if (opacity>100)   SetOpacity(element,100)
	else
	{
		SetOpacity(element,opacity);
		element.timer = window.setTimeout("ChangeOpacity('" + id + "'," + msDuration + "," + msStart + "," + fromO + "," + toO + ")",1);
	}
}

function swapImage(imageID, newImage)
{
	var foreground = document.getElementById(imageID);
	if(foreground==null)	return;
	SetOpacity(foreground,0);
	foreground.src = newImage;
	if (foreground.timer) window.clearTimeout(foreground.timer); 
	var startMS = (new Date()).getTime();
	foreground.timer = window.setTimeout("ChangeOpacity('" + imageID + "',3000," + startMS + ",0,100)",10);
}