Question concerning the customization of Google AdSense code

Hi Dear,

Hope you are doing well. Dear i have a concern regarding google customize java scirpt ad code. I have notice that form last 3 month my google customized ad code in not working properly. I had already search lost of in forums and search but i did not any fine reason. Can u check it from your end give me suggestion that why are not this is working properly. Below is my java script ad code:

<script type="text/javascript">
var google_adnum = 0;
function google_ad_request_done(google_ads) {
 var u = ''; var i;
 if (google_ads.length == 0) {
    return;
  } else {
      for (i = 0; i < google_ads.length; ++i) {
         u += '<span class="testart2"><a href="' + google_ads[i].url + '">' + google_ads[i].line1 + '</a></span> <span class="testart4"><a href="' + google_ads[i].url + '">' + google_ads[i].visible_url + '</a></span><br /><span class="testart3">' + google_ads[i].line2 + ' ' + google_ads[i].line3 + '</span>  ';
       if (i < google_ads.length - 1) u += ' <span class="testart5">&nbsp;</span> ';
      }
     u = '<div class="testart"><span class="testart1"><a href="' + google_info.feedback_url + '">Ads by Google</a></span> ' + u + '</div>';
    }
  google_adnum = google_adnum + google_ads.length;
  document.write(u);
  return;
}
google_ad_client = 'ca-pub-9372192619832074';google_ad_output = 'js';google_ad_type = 'text';google_feedback = 'on';google_language = 'en';google_encoding = 'utf8';
google_max_num_ads = '4';
google_ad_channel='9376826742';
</script><script type="text/javascript" src="index.jsp_files/show_ads.js"></script><script src="index.jsp_files/show_ads_impl.js"></script>

Thanks & Regards,
Sanjeev Saini