function banner(imgSource,url,alt,chance) {
this.imgSource = imgSource;
this.url = url;
this.alt = alt;
this.chance = chance;
}
function dispBanner() {
with (this) document.write("<A HREF=" + url + "><IMG SRC='" + imgSource + "' WIDTH=80 HEIGHT=80 BORDER=0 ALT='" + alt + "'></A>");
}
banner.prototype.dispBanner = dispBanner;
banners = new Array();
banners[0] = new banner("../../images/banner/drprint_brs.jpg",
                        "http://www.drprint.com target='_blank'",
                        "Dr Print",
                        30);
banners[1] = new banner("../../images/banner/timba_brs.jpg",
                        "",
                        "Timba",
                        20);
banners[2] = new banner("../../images/banner/daila_brs.jpg",
                        "http://www.dailapercussion.com target='_blank'",
                        "DA..ILA precedenza alla musica che è in te.",
                        35);
banners[3] = new banner("../../images/banner/udu_brs.jpg",
                        "",
                        "Ululati dall&#039;Underground",
                        30);
banners[4] = new banner("../../images/banner/pd_brs.gif",
                        "http://www.planet-drum.com target='_blank'",
                        "Planet Drum Webzine",
                        30);
banners[5] = new banner("../../images/banner/fabio_brs.jpg",
                        "http://www.fabioilfonico.com target='_blank'",
                        "Fabio Laurenti",
                        30);
banners[6] = new banner("../../images/banner/messe_brs.gif",
                        "",
                        "Planet Drum e DAILA al musikmesse",
                        90);


sum_of_all_chances = 0;
for (i = 0; i < banners.length; i++) {
sum_of_all_chances += banners[i].chance;
}
function randomBanner() {
chance_limit = 0;
randomly_selected_chance = Math.round((sum_of_all_chances - 1) * Math.random()) + 1;
for (i = 0; i < banners.length; i++) {
chance_limit += banners[i].chance;
if (randomly_selected_chance <= chance_limit) {
document.write("<A HREF=" + banners[i].url + "><IMG SRC='" + banners[i].imgSource + "' WIDTH=80 HEIGHT=80 BORDER=0 ALT='" + banners[i].alt + "'></A>");
return banners[i];
break;
      }
   }
}