function doZoom(onOff) {
	var u = String(window.location);

	if (u.indexOf("zoom=") != -1)
		u = u.replace("zoom="+(onOff ? 0 : 1), "zoom="+onOff);
	else
		u += (u.indexOf("?") == -1 ? "?" : "&")+"zoom="+onOff;

	window.location = u;
}