var img_width = "468";
var img_height = "60";
var img_title = "Instant Sales Letters";

var ad=new Array()
//insert here your images src
ad[0]='http://www.bowling-centers.com/images/instantsalesletters.gif';

var links=new Array()
//insert here your links
links[0]='http://instantsalesletters.com/?51109';

var xy=Math.floor(Math.random()*ad.length);
document.write('<a href="'+links[xy]+'" target="_blank"><img src="'+ad[xy]+'" width="'+img_width+'" height="'+img_height+'" alt="'+img_title+'"></a>');