//<![CDATA[ 

var image = new Array();

image[0] = 'images/header_interior_2.jpg'; 
image[1] = 'images/header_interior_2.jpg'; 

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