nav4on= new Image();
nav4on.src="http://festival.magnumphotos.com/images/nav_all_eventsR.gif";
nav4off= new Image();
nav4off.src="http://festival.magnumphotos.com/images/nav_all_events.gif";
nav1on= new Image();
nav1on.src="http://festival.magnumphotos.com/images/nav_exhibitionsR.gif";
nav1off= new Image();
nav1off.src="http://festival.magnumphotos.com/images/nav_exhibitions.gif";
nav2on= new Image();
nav2on.src="http://festival.magnumphotos.com/images/nav_filmR.gif";
nav2off= new Image();
nav2off.src="http://festival.magnumphotos.com/images/nav_film.gif";
nav3on= new Image();
nav3on.src="http://festival.magnumphotos.com/images/nav_special_eventsR.gif";
nav3off= new Image();
nav3off.src="http://festival.magnumphotos.com/images/nav_special_events.gif";
nav5on= new Image();
nav5on.src="http://festival.magnumphotos.com/images/nav_glanceR.gif";
nav5off= new Image();
nav5off.src="http://festival.magnumphotos.com/images/nav_glance.gif";

function img_act(imgName,PicName)
   {
    document [PicName].src = eval(imgName + ".src");
   }