var image = new Array();

image[0] = 'images/random/random-bottom_0.jpg' ;
image[1] = 'images/random/random-bottom_1.jpg' ;
image[2] = 'images/random/random-bottom_2.jpg' ;
image[3] = 'images/random/random-bottom_3.jpg' ;
image[4] = 'images/random/random-bottom_4.jpg' ;

var index = Math.floor(Math.random() * image.length);
document.write('<style type="text/css"> td.title { background-image: url('+ image[index] +') } </style>');