var banner=new Array()

banner[0]='<img src="img/ban1.jpg" alt="Puszcza Białowieska" width="600" height="230" border="0">'

banner[1]='<img src="img/ban2.jpg" alt="Puszcza Białowieska" width="600" height="230" border="0">'

banner[2]='<img src="img/ban3.jpg" alt="Puszcza Białowieska" width="600" height="230" border="0">'

banner[3]='<img src="img/ban4.jpg" alt="Puszcza Białowieska" width="600" height="230" border="0">'



var whichbanner=Math.floor(Math.random()*(banner.length))
document.write(banner[whichbanner])