window.addEventListener("load", function() { /* !!!przerobiæ na jquery w wolnej chwili!!! */
	var linki = document.getElementsByTagName('a');
	for (i = 0; i < linki.length; i++) {
		if (linki[i].parentNode.parentNode.id=='nav') {
			linki[i].onmouseover = function() {return opacity(this.id, 75, 100, 400)};
			linki[i].onmouseout = function() {return opacity(this.id, 100, 75, 400)};
		}
	}
}, false);

function opacity(id, opacStart, opacEnd, millisec) {
	var speed = Math.round(millisec / 100);
	var timer = 0;
	if (opacStart > opacEnd) {
		for (i = opacStart; i >= opacEnd; i--) {
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	} else if (opacStart < opacEnd) {
		for(i = opacStart; i <= opacEnd; i++) {
			setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
			timer++;
		}
	}
}

function changeOpac(opacity, id) {
	var object = document.getElementById(id).style;
	object.opacity = (opacity / 100);
}