/**
 * Реализация наследования в JavaScript. 
 * Основано на: http://www.kevlindev.com/tutorials/javascript/inheritance/
 */


ys = {}

ys.extend = function(subClass, baseClass) {
   function inheritance() {}
   inheritance.prototype = baseClass.prototype;

   subClass.prototype = new inheritance();
   subClass.prototype.constructor = subClass;
   subClass.baseConstructor = baseClass;
   subClass.superClass = baseClass.prototype;
}