/**
 * Custom button state handler for enabling/disabling button state. 
 * Called when the carousel has determined that the previous button
 * state should be changed.
 * Specified to the carousel as the configuration
 * parameter: prevButtonStateHandler
 **/
var handlePrevButtonState = function(type, args) {

    var enabling = args[0];
    var leftImage = args[1];
    if(enabling) {
        leftImage.src = "images/left-enabled.gif";    
    } else {
        leftImage.src = "images/left-disabled.gif";    
    }
    
};

/**
 * Custom button state handler for enabling/disabling button state. 
 * Called when the carousel has determined that the next button
 * state should be changed.
 * Specified to the carousel as the configuration
 * parameter: nextButtonStateHandler
 **/
var handleNextButtonState = function(type, args) {

    var enabling = args[0];
    var rightImage = args[1];
    
    if(enabling) {
        rightImage.src = "images/right-enabled.gif";
    } else {
        rightImage.src = "images/right-disabled.gif";
    }
};

var carousel;
var kerryPicsCarousel;

var changePic = function(e) {
	document.getElementById('bigPic').src = e.originalTarget.src;
	document.getElementById('desc').innerHTML = e.originalTarget.alt;
};

var changeKerryPic = function(e) {
	document.getElementById('bigPicKerry').src = e.originalTarget.src;
	document.getElementById('kerryDesc').innerHTML = e.originalTarget.alt;
};

var pageLoad = function() 
{
    carousel = new YAHOO.extension.Carousel("mycarousel", 
        {
            numVisible:        3,
            animationSpeed:    0.15,
            scrollInc:         3,
            navMargin:         20,
            size:              3
        }
    );
    kerryPicsCarousel = new YAHOO.extension.Carousel("kerryPicsCarousel", 
        {
            numVisible:        3,
            animationSpeed:    0.15,
            scrollInc:         3,
            navMargin:         20,
            prevElement:     "prev-arrowKerry",
            nextElement:     "next-arrowKerry",
            size:              8,
            prevButtonStateHandler:   handlePrevButtonState,
            nextButtonStateHandler:   handleNextButtonState
        }
    ); 
    YAHOO.util.Event.addListener([document.getElementById('mycarousel-item-1'), document.getElementById('mycarousel-item-2'), document.getElementById('mycarousel-item-3')], 'click', changePic);
    YAHOO.util.Event.addListener([document.getElementById('kerryPicsCarousel-item-1'), document.getElementById('kerryPicsCarousel-item-2'), document.getElementById('kerryPicsCarousel-item-3'), document.getElementById('kerryPicsCarousel-item-4'), document.getElementById('kerryPicsCarousel-item-5'), document.getElementById('kerryPicsCarousel-item-6'), document.getElementById('kerryPicsCarousel-item-7'), document.getElementById('kerryPicsCarousel-item-8')], 'click', changeKerryPic);
};
YAHOO.util.Event.addListener(window, 'load', pageLoad);