GK = (document.getElementById) ? 1 : 0;

plus = new Image();
plus.src = "./image/plus.gif";
minus = new Image();
minus.src = "./image/minus.gif";

function map_open(n) {
	if(! n) n = "";
	p = "sw" + n;
	i = "map" + n;
	o = "map_area" + n;
	img = (GK) ? document.getElementById(i).innerHTML : document.all(i).innerHTML;
	obj = (GK) ? document.getElementById(o) : document.all(o);
	if(obj.innerHTML == "") {
		obj.innerHTML = img;
		document.images[p].src = minus.src;
	}
	else {
		obj.innerHTML = "";
		document.images[p].src = plus.src;
	}
	return false;
}