var loadNextItems = function(type, args) {	
	
	var start = args[0];
	var last = args[1];
	var alreadyCached = args[2];
	
	if(!alreadyCached) {
		makeRequest(this, urlRequest, queryString, start, (last-start+1) * 2);
	}
};

var loadPrevItems = function(type, args) {
	
	var start = args[0];
	var last = args[1]; 
	var alreadyCached = args[2];

	if(!alreadyCached) {
		makeRequest(this, urlRequest, queryString, start, (last-start+1) * 2);
	}
};

var handlePrevButtonState = function(type, args) {
	var enabling = args[0];
	var leftImage = args[1];
	if(enabling) {
		leftImage.src = urlSlideThumbs + "layouts/" + prefLayout + "-left-enabled.gif";	
	} else {
		leftImage.src = urlSlideThumbs + "layouts/" + prefLayout + "-left-disabled.gif";	
	}
};

var handleNextButtonState = function(type, args) {
	var enabling = args[0];
	var rightImage = args[1];
	
	if(enabling) {
		rightImage.src = urlSlideThumbs + "layouts/" + prefLayout + "-right-enabled.gif";
	} else {
		rightImage.src = urlSlideThumbs + "layouts/" + prefLayout + "-right-disabled.gif";
	}
	
};

var showButtons = function(type, args) {
	YAHOO.util.Dom.setStyle("next-arrow", "visibility", "visible");
	YAHOO.util.Dom.setStyle("prev-arrow", "visibility", "visible");
};

var carousel;

var pageLoad = function() 
{
	document.getElementById("prev-arrow").src = urlSlideThumbs + "layouts/" + prefLayout + "-left-disabled.gif";
	document.getElementById("next-arrow").src = urlSlideThumbs + "layouts/" + prefLayout + "-right-enabled.gif";
	
	carousel = new YAHOO.extension.Carousel("dhtml-carousel", 
		{
			numVisible:        5,
			animationSpeed:    0.4,
			scrollInc:         2,
			loadInitHandler:   loadInitialItems,
			prevElement:       "prev-arrow",
			nextElement:       "next-arrow",
			loadNextHandler:   loadNextItems,
			loadPrevHandler:   loadPrevItems,
			prevButtonStateHandler:   handlePrevButtonState,
			nextButtonStateHandler:   handleNextButtonState
		}
	);

};

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

var handleSuccess = function(callbackResponse)
{
	var start = callbackResponse.argument[0];
	var numResults = callbackResponse.argument[1];
	var carousel = callbackResponse.argument[2];

  	if(callbackResponse.responseXML !== undefined) {
	  	
	  	var node_return = callbackResponse.responseXML.documentElement;
	    if (node_return.nodeName == "return")
	    {				
		    carousel.setProperty("size", node_return.getAttribute("total") * 1, true);
		    		    
		    var tripInnerHTML;    
	        for (x=0;x<node_return.childNodes.length;x++)
	        {
		        node_item = node_return.childNodes[x];
		        if ((node_item.nodeType == 1) || (node_item.nodeType == 3))
		        {
			        if (node_item.nodeName == "item")
			        {
						tripInnerHTML = '<a href="' + urlProdInfo + node_item.getAttribute("cd") + '&start=' + (start+x) + '"><img src="' + urlProdImg + node_item.getAttribute("img") + '" width="75" height="75"/></a>';
				        carousel.addItem(start+x, tripInnerHTML);
			        }
		        }
	        }
	    }
		showButtons();
     }
};

var handleFailure = function(o)
{
     var result = o.status + " " + o.statusText;
     //alert("Transaction failed.  The error is: " + result);
};

function URLencode(sStr) {
    return escape(sStr).replace(/\+/g, '%2B').replace(/\"/g,'%22').replace(/\'/g, '%27').replace(/\//g,'%2F');
}

var makeRequest = function(carousel, url, query, start, numResults)
{
	var params = '?query=' + URLencode(query) + '&start=' + start + '&results=' + numResults; 

	var callback =
	{
  		success: handleSuccess,
  		failure: handleFailure,
  		argument: [start, numResults, carousel]
	};
	
	var sUrl = url + params;
	YAHOO.util.Connect.asyncRequest("GET", sUrl, callback, null);
};