if (document.images) 
  {
   but1_on = new Image
   but1_off = new Image
   but2_on = new Image
   but2_off = new Image
   but3_on = new Image
   but3_off = new Image
   but4_on = new Image
   but4_off = new Image
   but5_on = new Image
   but5_off = new Image
   but6_on = new Image
   but6_off = new Image
   but1_on.src='img/01.but_aktualnosci_on.gif'
   but1_off.src='img/01.but_aktualnosci_off.gif'
   but2_on.src='img/02.but_uslugi_on.gif'
   but2_off.src='img/02.but_uslugi_off.gif'
   but3_on.src='img/03.but_onas_on.gif'
   but3_off.src='img/03.but_onas_off.gif'
   but4_on.src='img/04.but_faq_on.gif'
   but4_off.src='img/04.but_faq_off.gif'
   but5_on.src='img/05.but_siec_on.gif'
   but5_off.src='img/05.but_siec_off.gif'
   but6_on.src='img/06.but_kontakt_on.gif'
   but6_off.src='img/06.but_kontakt_off.gif'
  }
  else
  {
   but1_on=""
   but1_off=""
   but2_on=""
   but2_off=""
   but3_on=""
   but3_off=""
   but4_on=""
   but4_off=""
   but5_on=""
   but5_off=""
   but6_on=""
   but6_off=""
   document.but1=""
   document.but2=""
   document.but3=""
   document.but4=""
   document.but5=""
   document.but6=""
  }


// End -->