function prozornost(obj, opacity) {
	opacity = (opacity == 100)?99.999:opacity;

	// IE/Win
	obj.style.filter = "alpha(opacity:"+opacity+")";

	// Safari<1.2, Konqueror
	obj.style.KHTMLOpacity = opacity/100;

	// Older Mozilla and Firefox
	obj.style.MozOpacity = opacity/100;

	// Safari 1.2, newer Firefox and Mozilla, CSS3
	obj.style.opacity = opacity/100;
}