Code javascript radom ngẫu nhiên hình ảnh quảng cáo khi refesh tab window

----------------------- random-banner-refesh window --------------------------------------
<script type="text/javascript">
//Javascript Created by Computerhope http://www.computerhope.com
//store the quotations in arrays
var images = [], 
index = 0;
images[0] = "<a href = 'http://www.computerhope.com/index.htm' target='blank'><img src='https://3.bp.blogspot.com/…/e10MP9mkqWEHo6T…/s1600/v9bet.gif' alt='Visit Computer Hope'></a>";
images[1] = "<a href = 'http://www.computerhope.com/history/index.htm' target='blank'><img src='https://3.bp.blogspot.com/…/__UBZ_jMZfwcl_…/s1600/188bet.gif' alt='Computer History'></a>";
index = Math.floor(Math.random() * images.length);
document.write(images[index]);
//done
</script>
----- end-random-banner-refesh window-----