function banner() {
};

banner = new banner();
number = 0;

// bannerArray
banner[number++] = "<a href='http://www.swazibank.co.sz/' target='_blank'><img src='ads/swazibank.gif' width='971' border='0'></a>"
banner[number++] = "<a href='http://www.torgaoptical.co.za/' target='_blank'><img src='ads/torgaoptical.gif' width='971' border='0'></a>"

// keep adding items here...

increment = Math.floor(Math.random() * number);