(function() {
    var Event = YAHOO.util.Event,
        Dom   = YAHOO.util.Dom,
        lang  = YAHOO.lang,
        slider, 
        bg="slider-bg", thumb="slider-thumb" 

    // The slider can move 0 pixels up
    var topConstraint = 0;

    // The slider can move 200 pixels down
    var bottomConstraint = 120;

    // Custom scale factor for converting the pixel offset into a real value
    var scaleFactor = 1.5;

    // The amount the slider moves when the value is changed with the arrow
    // keys
    var keyIncrement = 20;
    var tickSize = 20;


    Event.onDOMReady(function() {

        slider = YAHOO.widget.Slider.getVertSlider(bg, 
                         thumb, topConstraint, bottomConstraint,tickSize);

        slider.getRealValue = function() {
            return Math.round(this.getValue() * scaleFactor);
        }

        slider.subscribe("slideEnd", function(offsetFromStart) {
            zoomInOut(this.getValue());
        });


        // set an initial value
        //slider.setValue(0);



        // Listen for keystrokes on the form field that displays the
        // control's value.  While not provided by default, having a
        // form field with the slider is a good way to help keep your
        // application accessible.
        Event.on(textfield, "keydown", function(e) {

            // set the value when the 'return' key is detected
            if (Event.getCharCode(e) === 13) {
                var v = parseFloat(this.value, 10);
                v = (lang.isNumber(v)) ? v : 0;

                // convert the real value into a pixel offset
                slider.setValue(Math.round(v/scaleFactor));
            }
        });
        
    });
})();