function RandInt(min, max) {
  var div = (max - min) + 1
  var randNum = Math.random()
  for (var i = 0; i <= div - 1; i++) {
    if (randNum >= i / div && randNum < (i+1) / div) {
      return i + min
    }
  }
}

var maxAd = 1;
var adArr = new Array(maxAd);

adArr[0] = ' <script type="text/javascript"> ' + '  google_ad_client = "pub-3824147731508522"; ' + ' google_ad_width = 468; ' + ' google_ad_height = 15;' + ' google_ad_format = "468x15_0ads_al"; ' + 'google_ad_type = "text_image"; ' + 
            'google_ad_slot = "7782872365";' + ' </script> ' + ' <script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> ' + ' </script>'; + '</table>'
            
            
var currAd = RandInt(0, maxAd - 1);
for (var j = 0; j < maxAd; j++){
  if (currAd == j) document.write(adArr[j]);
}