var url = "http://www.fan-strefa.pl/ad5/adv.html?"+
          ad_color_border+"&"+
          ad_color_bg+"&"+
          ad_color_link+"&"+
          ad_color_url+"&"+
          ad_color_text;
 
document.write('<iframe width="728" height="90" scrolling="no" frameborder="0" src="'+url+'"></iframe>');