JavaScript Klassen vererben

var Slider = function(newConfig) {
  var private Variablen/Methoden;

  this.next = function() {
    ...
  }

  slideMove = function() { // private Funktion
    ...
  }
}

var GallerySlider = function(newConfig) {
  var private Variablen/Methoden (nur für Galerie)

  createGallery() {
    ...
  }
}

getFunctionInner = function(code) {
	var splitCode;
	if (typeof(code) === 'function') {
		code = code.toString();
	}
	
	splitCode = code.split('{');
	splitCode.shift();
	code = splitCode.join('{');
	
	code = code.substr(0, code.lastIndexOf('}'));
	
	return code;
}

var GallerySlider = function(newConfig) {
	// Basisklasse laden	
	eval(getFunctionInner(Slider));
        ...
}

GallerySlider.prototype = Slider;

Slider.call(this, newConfig);

eval(getFunctionInner(Slider));

var o = new GallerySlider();
o instanceof GallerySlider === true
o instanceof Slider === true // Update: false
o instanceof Object === true