function obbie_ad_get(channel, size) {
   var id = (new Date()).getTime() + parseInt(Math.random() * 100000);
   if(typeof(channel) == 'undefined') channel = 'general';
   if(typeof(size) == 'undefined') size = '468x60';
   document.write(
      '<div id="obbie_ad_' + id + '"><script type="text/javascript" ' +
      'src="http://adserver.obbie.pl/' + id +
      '/' + channel + '/' + size + '/ad.js" charset="UTF-8"></script></div>'
      );
}