(function(){
	shuffle = function(array) {
		var i = array.length;
		while(i){
			var j = Math.floor(Math.random()*i);
			var t = array[--i];
			array[i] = array[j];
			array[j] = t;
		}
		return array;
	}
	
	var ads = [{"src":"http:\/\/farm4.static.flickr.com\/3130\/2400619148_627ec92636_o.jpg","alt":"\u30a2\u30c0\u30eb\u30c8SNS","target":"_blank","weight":1,"url":"http:\/\/ad.heypo.com\/click\/200"},{"src":"http:\/\/farm3.static.flickr.com\/2186\/2400630358_d982024627_o.jpg","alt":"\u30b2\u30fc\u30e0\u306e\u3088\u3046\u306a\u51fa\u4f1a\u3044","target":"_blank","weight":1,"url":"http:\/\/ad.heypo.com\/click\/202"},{"src":"http:\/\/media.heypo.com\/uploads\/assets\/okinny\/728-90-3.jpg","alt":"\u30a2\u30c0\u30eb\u30c8\u753b\u50cf\u30d6\u30c3\u30af\u30de\u30fc\u30af\u30b5\u30a4\u30c8[ \u30aa\u30ad\u30cb\u30fc ]","target":"_blank","weight":1,"url":"http:\/\/ad.heypo.com\/click\/334"}];
	if (ads.length < 1) return;
	
	var tmp = [];
	for (var i = 0; i < ads.length; i++) {
		for (var j = 0; j < ads[i].weight; j++) {
			tmp.push(ads[i]);
		}
	}
	
	var ad = shuffle(tmp).shift();
	document.getElementById('ad-zone-21').innerHTML = '<a href="' + ad.url +'" target="' + ad.target +'"><img src="' + ad.src +'" alt="' + ad.alt +'" /></a>';
})();