imgA01on = new Image(119,167);
imgA01on.src = "img/area_south_ovr.gif";
imgA01off = new Image(119,167);
imgA01off.src = "img/area_south.gif";

imgA02on = new Image(119,167);
imgA02on.src = "img/area_west_ovr.gif";
imgA02off = new Image(119,167);
imgA02off.src = "img/area_west.gif";

imgA03on = new Image(119,167);
imgA03on.src = "img/area_central_ovr.gif";
imgA03off = new Image(119,167);
imgA03off.src = "img/area_central.gif";

imgA04on = new Image(119,167);
imgA04on.src = "img/area_east_ovr.gif";
imgA04off = new Image(119,167);
imgA04off.src = "img/area_east.gif";

function imgon(imgname) {
        document[imgname].src = eval(imgname + "on.src");
}
function imgoff(imgname) {
        document[imgname].src = eval(imgname + "off.src");
}