var images = new Array();

images[0] = "phase1.gif"; 
images[1] = "phase2.gif";
images[2] = "phase3.gif";
images[3] = "phase4.gif";
images[4] = "phase5.gif"; 
images[5] = "phase6.gif";
images[6] = "phase7.gif";
images[7] = "phase8.gif";
images[8] = "phase9.gif";

var number = images.length;
var increment = Math.floor(Math.random() * number);
var headerChoice = '<img src="http://www.photocopiersrus.co.uk/images/header/'+images[increment]+'" border="0" width="1055" height="161">'
document.write(headerChoice) ;