document.write('<br>');

l=Math.floor(Math.random()*1000);

switch(l % 4)
{
  case 0:
  case 1:
  case 2:
  case 3:
    document.write('<script language="javascript" src="http://www.21stars.net/top_image/ads_netjokes_468x60.js"></script>');
    document.write('<script language="javascript" src="http://www.21stars.net/top_image/ads_scanzone_0x0.js"></script>');
    break;
  default:
}