var photos = new Array(

'<img alt="American Avocet" height="400" src="images/american%20avocet.png" style="float: right" width="268">',
'<img alt="Whistling Duck" height="400" src="images/bb%20whistling%20duckand%20young.png" style="float: right" width="268">',
'<img alt="Bells Vireo" height="400" src="images/bells%20vireo.png" style="float: right" width="268">',
'<img alt="10-day old Blak Neck Stilt chick" height="400" src="images/black%20bellied%20plover%20breeding.png" style="float: right" width="268">',
'<img alt="Bobolink" height="400" src="images/bobolink.png" style="float: right" width="268">',
'<img alt="Black Bellied Plover Breeding" height="400" src="images/black%20bellied%20plover%20breeding.png" style="float: right" width="268">',
'<img alt="Black Bellied Plover Breeding" height="400" src="images/black%20bellied%20plover%20breeding.png" style="float: right" width="268">',
'<img alt="Black Bellied Plover Breeding" height="400" src="images/black%20bellied%20plover%20breeding.png" style="float: right" width="268">'

);

var max = photos.length;
var num = Math.floor((Math.random() * max));
document.writeln(photos[num]);