banners = new Array(2);
banners[0] = "
PJ Harvey
White Chalk
19,90 no Submarino";
banners[1] = "
Queens of the Stone Age
Era Vulgaris
19,90 no Submarino";
//calculate a random index
index = Math.floor(Math.random() * banners.length);
//display the banner
document.write(banners[index]);