img = new Array();
img[0] = "/img/img01.jpg";
img[1] = "/img/img02.jpg";
img[2] = "/img/img03.jpg";
img[3] = "/img/img04.jpg";
img[4] = "/img/img05.jpg";
img[5] = "/img/img06.jpg";
n = Math.floor(Math.random()*img.length);
document.write("<img src='"+img[n]+"' border='0'>");