var 
MNews = new Array(); 

MNews[0]= '<iframe src="http://www.zura.com.br/vitrine?keywords=roteador&size=8&pr=3561&site=4413&template=97" width="300px" height="255px" scrolling="no" frameborder="0" ></iframe>'

MNews[1]= '<iframe src="http://www.zura.com.br/vitrine?keywords=filmadora&size=8&pr=3561&site=4413&template=95" width="300px" height="255px" scrolling="no" frameborder="0" ></iframe>'

MNews[2]= '<iframe src="http://www.zura.com.br/vitrine?keywords=liquidificador&size=8&pr=3561&site=4413&template=94" width="300px" height="255px" scrolling="no" frameborder="0" ></iframe>'

MNews[3]= '<iframe src="http://www.zura.com.br/vitrine?keywords=fog%E3o&size=8&pr=3561&site=4413&template=93" width="300px" height="255px" scrolling="no" frameborder="0" ></iframe>'

MNews[4]= '<iframe src="http://www.zura.com.br/vitrine?keywords=notebook+netbook&size=8&pr=3561&site=4413&template=99" width="300px" height="255px" scrolling="no" frameborder="0" ></iframe>'

var Numero = Math.floor(Math.random()*5);
document.write(MNews[Numero]);