Cannot extend my javascript object with Prototype
<p>I have this code:</p>

<pre><code>var Flippable = function( options, element ) {
    this.$el    = $( element );
    this._init( options );
};

Flippable.prototype     = {
    _init               : function( options ) {

        this.options        = $.extend( true, {}, $.Flips.defaults, options );
        this.$pages         = this.$el.children( 'div.f-page' );
        this.pagesCount     = this.$pages.length;
        this.History        = window.History;
        this.currentPage    = this.options.current;
        this._validateOpts();
        this._getWinSize();
        this._getState();
        this._layout();
        this._initTouchSwipe();
        this._loadEvents();
        this._goto();

    },
    foo: function(){alert("foo");}
}
</code></pre>

<p>But when I call Flipppable.foo(), I get undefined. Any ideas where my syntax is off?</p>

<p>Thanks!</p>

<p>Chris</p>

<p>** Update **</p>

<p>I"m creating a plugin like so:</p>

<pre><code>$.fn.flippable = function( method ) {

// Method calling logic
if ( Flippable[method] ) {
  return Flippable[ method ].apply( this, Array.prototype.slice.call( arguments, 1 ));
} else if ( typeof method === 'object' || ! method ) {
  return Flippable._init.apply( this, arguments );
</code></pre>

<p>Uncaught TypeError: Cannot call method 'apply' of undefined
    } else {
      $.error( 'Method ' +  method + ' does not exist on jQuery.flippable' );
    }    </p>

<p>};</p>

<p>It borks on line:</p>

<pre><code>return Flippable._init.apply( this, arguments );
</code></pre>

<p>_init is undefined.</p>
