// changes the opacity for different browsers 
function SetOpacity(el, opacity) 
{ 
	if (!el) return;
	el.opacity = opacity;
	el.style.opacity = (opacity / 100); 
	el.style.MozOpacity = (opacity / 100); 
	el.style.KhtmlOpacity = (opacity / 100); 
	el.style.filter = "alpha(opacity=" + opacity + ")"; 
} 

// changes the opacity for different browsers 
function SetOpacityById(id, opacity) 
{ 
	SetOpacity(document.getElementById(id), opacity);
} 

// blending by opacity
function BlendOpacity(id, opacity, delta, limit, time) 
{ 
	var el = document.getElementById(id);
	if (!el) return;
	
	clearTimeout(el.timeout);

	SetOpacity(el, opacity);
	if (delta == 0 || opacity == limit)
		return;

	opacity = Math.max(0, Math.min(100, opacity + delta));
	if ((delta > 0 && opacity >= limit) || (delta < 0 && opacity <= limit))
		opacity = limit;
	
	el.timeout = setTimeout("BlendOpacity('" + id + "'," + opacity + "," + delta + "," + limit + "," + time + ")", time); 
}