var wall = new Array();
wall[0] = "images/visual0.jpg";
wall[1] = "images/visual1.jpg";
wall[2] = "images/visual2.jpg";
wall[3] = "images/visual3.jpg";
wall[4] = "images/visual4.jpg";
wall[5] = "images/visual5.jpg";
wall[6] = "images/visual6.jpg";
wall[7] = "images/visual7.jpg";
wall[8] = "images/visual8.jpg";
wall[9] = "images/visual9.jpg";

var rnd = Math.floor((Math.random() * 100)) % wall.length;
document.write('<style type="text/css">#visual { background:url(' , wall[rnd] , ') no-repeat; }</style>');