var mess = new Array('<img src="images/lionfish.jpg" alt="Lionfish" width="481" height="318" border="0" />','<img src="images/lipfish.jpg" alt="Pompano" width="561" height="282" border="0" />','<img src="images/pointyfish.jpg" alt="Butterflyfish" width="428" height="293" border="0" />','<img src="images/toothyfish.jpg" alt="Spadefish" width="441" height="310" border="0" />');
var max = mess.length;
var num = Math.floor((Math.random() * max));
document.writeln(mess[num]);