var how_many_ads = 3;
var now = new Date()
var sec = now.getSeconds()
var ad = sec % how_many_ads;
ad +=1;

if (ad==1) {
alt="Penn Township Fire Department";
banner="http://www.penntownship.org/imgs/fireboys.gif";
width="263";
height="82";
pagetarg="_top";
}
if (ad==2) {
alt="Penn Township Police Department";
banner="http://www.penntownship.org/imgs/badboys.gif";
width="263";
height="82";
pagetarg="main";
}
if (ad==3) {
alt="Penn Township Road Department";
banner="http://www.penntownship.org/imgs/roadboys.gif";
width="263";
height="82";
pagetarg="main";
}
document.write('<img src=\"' + banner + '\" width=')
document.write(width + ' height=' + height + ' ');
document.write('alt=\"' + alt + '\" border=0>');