var map= new Image();
map.src = "/images/uploads/map.gif";

var na = new Image();
na.src = "/images/uploads/map_northamerica.gif";

var sa = new Image();
sa.src = "/images/uploads/map_southamerica.gif";

var africa = new Image();
africa.src = "/images/uploads/map_africa.gif";

var oz = new Image();
oz.src = "/images/uploads/map_australia.gif";

var asia = new Image();
asia.src = "/images/uploads/map_asia.gif"; 

var eur = new Image();
eur.src = "/images/uploads/map_europe.gif";

// Function to "activate" images.
function imgAct(imgName) {

  document['posmap'].src = eval(imgName + ".src");

}

function imgDeact(imgName) {

  document['posmap'].src = eval("map.src");

}