var $ = function (id) {
	return document.getElementById(id);
}

var Seasons = {
	items: new Array(),
	curentItem: 0,
	changeSpeed: 10000,
	alphaFlag: true,

	alpha: function(id, value) {
		if (document.all && !window.opera) $(id).style.filter = 'alpha(opacity=' + value * 100 + ')';
		else $(id).style.opacity = value;
	},

	show: function() {
		var tempId = Seasons.items[Seasons.curentItem].id;
		if (Seasons.curentItem != -1)
			$('seasons').innerHTML = "<div id='seasons_" + tempId + "' style='display: block; position: absolute;'><img src='images/kontakt/siedziba_onyx_" + tempId + ".jpg' /></div>";
		Seasons.intervalId = window.setInterval('Seasons.change()', Seasons.changeSpeed);
	},

	change: function() {
		var nextItem = 0, tempId;
		nextItem = parseInt(Seasons.curentItem + 1);
		if (nextItem >= Seasons.items.length) nextItem = 0;

		if (Seasons.curentItem != nextItem && Seasons.alphaFlag) {
			tempId = Seasons.items[nextItem].id;
			$('seasons').innerHTML += "<div id='seasons_" + tempId + "' style='display: none; position: absolute;'><img src='images/kontakt/siedziba_onyx_" + tempId + ".jpg' /></div>";
			Seasons.alpha('seasons_' + tempId, 0);
			Seasons.items[nextItem].alpha = 0;
			$('seasons_' + Seasons.items[nextItem].id).style.display = 'block';
			Seasons.alpha('seasons_' + Seasons.items[Seasons.curentItem].id, 1);
			Seasons.items[Seasons.curentItem].alpha = 1;
			Seasons.setAlpha(Seasons.curentItem, nextItem);
			Seasons.curentItem = nextItem;
			Seasons.alphaFlag = false;
		}
	},

	setAlpha: function(idOld, idNew) {
		if (Seasons.items[idNew].alpha < 1) {
			Seasons.items[idNew].alpha += 0.05;
			Seasons.items[idOld].alpha -= 0.05;
			Seasons.alpha('seasons_' + Seasons.items[idNew].id, Seasons.items[idNew].alpha);
			Seasons.alpha('seasons_' + Seasons.items[idOld].id, Seasons.items[idOld].alpha);
			window.setTimeout('Seasons.setAlpha('+ idOld + ',' + idNew + ')', 50);
		}
		else {
			$('seasons').removeChild($('seasons_' + Seasons.items[idOld].id));
			Seasons.alphaFlag = true;
		}
	},

	setCurentItem: function(nextItem) {
		var tempId;
		window.clearInterval(Seasons.intervalId);

		if (Seasons.curentItem != nextItem && Seasons.alphaFlag) {
			tempId = Seasons.items[nextItem].id;
			$('seasons').innerHTML += "<div id='seasons_" + tempId + "' style='display: none; position: absolute;'><img src='images/kontakt/siedziba_onyx_" + tempId + ".jpg' /></div>";
			Seasons.alpha('seasons_' + tempId, 0);
			Seasons.items[nextItem].alpha = 0;
			$('seasons_' + Seasons.items[nextItem].id).style.display = 'block';
			Seasons.alpha('seasons_' + Seasons.items[Seasons.curentItem].id, 1);
			Seasons.items[Seasons.curentItem].alpha = 1;
			Seasons.setAlpha(Seasons.curentItem, nextItem);
			Seasons.curentItem = nextItem;
			Seasons.alphaFlag = false;
		}
	},


	init: function() {
		for(var item in this.items) {
			if (this.items[item].visible == 1) {
				Seasons.curentItem = item;
				break;
			}
		}
		this.show();
	}
}