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] = '<div style="position: absolute; width: 100px; height: 100px; z-index: 1; right: 0px; top: 0px" id="katman1">' + 
			'<img border="0" src="/images/main/bayrak.gif" width="100" height="100" title="Ne Mutlu Türküm Diyene!"></div>';


var currAd = RandInt(0, maxAd - 1);
for (var j = 0; j < maxAd; j++){
  if (currAd == j) document.write(adArr[j]);
}