//<![CDATA[ 
var image = new Array();

image[0] = 'http://audition.playpark.com/images/bg/bg_head01.jpg'; 
image[1] = 'http://audition.playpark.com/images/bg/bg_head02.jpg'; 
image[2] = 'http://audition.playpark.com/images/bg/bg_head03.jpg';
image[3] = 'http://audition.playpark.com/images/bg/bg_head04.jpg';
image[4] = 'http://audition.playpark.com/images/bg/bg_head05.jpg';

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