/**
 * Custom inital load handler. Called when the carousel loads the initial
 * set of data items. Specified to the carousel as the configuration
 * parameter: loadInitHandler
 **/
var loadInitialItems = function(type, args) {

	var start = args[0];
	var last = args[1]; 

	load(this, start, last);	
};

/**
 * Custom load next handler. Called when the carousel loads the next
 * set of data items. Specified to the carousel as the configuration
 * parameter: loadNextHandler
 **/
var loadNextItems = function(type, args) {	

	var start = args[0];
	var last = args[1]; 
	var alreadyCached = args[2];
	
	if(!alreadyCached) {
		load(this, start, last);
	}
};

/**
 * Custom load previous handler. Called when the carousel loads the previous
 * set of data items. Specified to the carousel as the configuration
 * parameter: loadPrevHandler
 **/
var loadPrevItems = function(type, args) {
	var start = args[0];
	var last = args[1]; 
	var alreadyCached = args[2];
	
	if(!alreadyCached) {
		load(this, start, last);
	}
};

var load = function(carousel, start, last) {
	for(var i=start;i<=last;i++) {
		carousel.addItem(i, fmtItem(tabPages[i-1]));
	}
};

var changePage = function(e, args) {
	var carousel = args[0];
	var pageNum = args[1];
	
	carousel.scrollTo(pageNum);
};

/**
 * You must create the carousel after the page is loaded since it is
 * dependent on an HTML element (in this case 'dhtml-carousel'.) 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("dhtml-carousel", 
		{
			numVisible:        1,
			animationSpeed:    0.60,
			scrollInc:         1,
			size:              4,
			navMargin:         0,
			loadInitHandler:   loadInitialItems,
			loadNextHandler:   loadNextItems,
			loadPrevHandler:   loadPrevItems
		}
	);
	YAHOO.util.Event.addListener(this.carouselNext, "click", this._scrollNext, this);

	YAHOO.util.Event.addListener("tab1", "click", changePage, [carousel, 1]);
	YAHOO.util.Event.addListener("tab2", "click", changePage, [carousel, 2]);
	YAHOO.util.Event.addListener("tab3", "click", changePage, [carousel, 3]);
	YAHOO.util.Event.addListener("tab4", "click", changePage, [carousel, 4]);
};

/**
 * Since carousel.addItem uses an HTML string to create the interface
 * for each carousel item, this method formats the HTML for an LI.
 **/
var fmtItem = function(tabPage) {

  	var innerHTML = 
  		'<img src="' + 
  		tabPage + 
  		'"/>';
  
	return innerHTML;
	
};


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