function banner() {
};

banner = new banner();
number = 0;

// bannerArray
banner[number++] = "<a href='photos-india.htm'><img border='0' src='random-link/floral_photography4.jpg'></a>"
banner[number++] = "<a href='goa-tourism-photo.htm'><img border='0' src='random-link/goa_panjim.jpg'></a>"
banner[number++] = "<a href='photo-tourism-kashmir.htm'><img border='0' src='random-link/kashmir-tourism.jpg'></a>"
banner[number++] = "<a href='photography-konkan.htm'><img border='0' src='random-link/elephant-calves.jpg'></a>"
// keep adding items here...

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

document.write(banner[increment]);