var ads = [];
ads.push(['<a href="http://www.cptv.com.cn" target="_blank"><img src="http://www.cptv.com.cn/system/template/front/default/media/images/ad2012.gif" height="65" width="380" border="0"></a>', 1329494400, 1326816000]);
var index = Math.floor(Math.random()*ads.length);
var today = new Date();
var i = 0;
while(((ads[index][1] > 0 && ads[index][1] * 1000 > today) 
|| ((ads[index][2] > 0 && ads[index][2] * 1000 < today))) 
&& i < 30) {
index = Math.floor(Math.random()*ads.length);
i++;
}
document.write(ads[index][0]);