javascript inheritance.

gistfile1.js

var extender = function(initializer){
    var parent  = this;
    var child   = function(){
        parent.apply(this,arguments);
        if(initializer) initializer.apply(this,arguments);
    }

    var Surrogate = function(){this.constructor = child; };
    Surrogate.prototype = parent.prototype;
    child.prototype = new Surrogate();

    child.__super__ = parent.prototype;
    child.extend = semetric.extend;
    return child;
}

// usage
var GenericModel = function(){}
GenericModel.extend = extender;

var SpecificModel = GenericModel.extend(function(data){
  // do something with the nice data here.
});