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

if (ad==1) 
{
google_ad_client = "pub-5278981701997398";
google_ad_width = 120;
google_ad_height = 240;
google_ad_format = "120x240_as";
google_ad_type = "text";
google_ad_channel = "";
google_color_border = "CCCC99";
google_color_bg = "FFFFFF";
google_color_link = "000000";
google_color_text = "333333";
google_color_url = "666666";
with (document) {
write("<script type='text/javascript' src='http://pagead2.googlesyndication.com/pagead/show_ads.js'>");
write("<\/script>");
}