void OnGUI()
{
c1a = GUILayout.TextField(c1a);
c1o = GUILayout.TextField(c1o);
c2a = GUILayout.TextField(c2a);
c2o = GUILayout.TextField(c2o);
try {
var c1 = new Geolocation(
latitude: float.Parse(c1a),
longitude: float.Parse(c1o));
var c2 = new Geolocation(
latitude: float.Parse(c2a),
longitude: float.Parse(c2o));
GUILayout.Label(c1.Distance(c2).ToString());
} catch (FormatException) {
GUILayout.Label("FormatException");
}
}