function addLocalEvent (o, t, f, l) {
	var d = 'addEventListener', n = 'on' + t, rO = o, rT = t, rF = f, rL = l;
	if (o[d] && !l) return o[d](t, f, false);
	if (!o._evts) o._evts = {};
	if (!o._evts[t]) {
		o._evts[t] = o[n] ? { b: o[n] } : {};
		o[n] = new Function('e',
			'var r = true, o = this, a = o._evts["' + t + '"], i; for (i in a) {' +
			'o._f = a[i]; r = o._f(e||window.event) != false && r; o._f = null;' +
			'} return r');
		if (t != 'unload') addEvent(window, 'unload', function() {removeEvent(rO, rT, rF, rL);});
	}
	if (!f._i) f._i = addEvent._i++;
	o._evts[t][f._i] = f;
}

function showNav() {
  document.getElementById("navHolderDiv").style.height = "600px";
}
function hideNav() {
  document.getElementById("navHolderDiv").style.height = "112px";
}

var curOS ;
if (navigator.appVersion.indexOf("Win")!=-1) curOS="Windows";
else if (navigator.appVersion.indexOf("Mac")!=-1) curOS="MacOS";
else if (navigator.appVersion.indexOf("X11")!=-1) curOS="UNIX";
else if (navigator.appVersion.indexOf("Linux")!=-1) curOS="Linux";
else curOS="unknown";