var img = new Array();
img[0] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head01.jpg" alt="LOWLIFE" />';
img[1] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head02.jpg" alt="LOWLIFE" />';
img[2] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head03.jpg" alt="LOWLIFE" />';
img[3] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head04.jpg" alt="LOWLIFE" />';
img[4] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head05.jpg" alt="LOWLIFE" />';
img[5] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head06.jpg" alt="LOWLIFE" />';
img[6] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head07.jpg" alt="LOWLIFE" />';
img[7] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head08.jpg" alt="LOWLIFE" />';
img[8] = '<img src="http://www.lowlife-japan.com/img/mainvisual/head09.jpg" alt="LOWLIFE" />';

var no = Math.floor(Math.random() * img.length);
document.write(img[no]);