/**
 * 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";
    }
    
};


/**
 * You must create the carousel after the page is loaded since it is
 * dependent on an HTML element (in this case 'mycarousel'.) See the
 * HTML code below.
 **/
var carousel; // for ease of debugging; globals generally not a good idea
var pageLoad = function() 
{
    carousel = new YAHOO.extension.Carousel("mycarousel", 
        {
            numVisible:        2,
            animationSpeed:    0.15,
            scrollInc:         1,
            navMargin:         25,
            prevElement:     "prev-arrow",
            nextElement:     "next-arrow",
            size:              2,
			wrap:              true,
            prevButtonStateHandler:   handlePrevButtonState,
            nextButtonStateHandler:   handleNextButtonState
        }
    );

};

YAHOO.util.Event.addListener(window, 'load', pageLoad);