(function($)
{
	function vis()
	{
	    return li.slice(curr).slice(0,v);
	};
	
	function go(to, skipCheck)
	{
	    if(!running)
	    {
	        if(o.beforeStart)
	        {
	            o.beforeStart.call(this, vis());
	        }
	        
	        if(!skipCheck)
	        {
	            checkItems();
	        }
	        
	        var prevSpeed = o.speed;
	        
	        if(o.circular)
	        {            // If circular we are in first or last, then goto the other end
	            if(to<=o.start-v-1)
	            {           // If first, then goto last
	                ul.css(animCss, -((itemLength-(v*2))*liSize)+"px");
	                // If "scroll" > 1, then the "to" might not be equal to the condition; it can be lesser depending on the number of elements.
	                curr = to==o.start-v-1 ? itemLength-(v*2)-1 : itemLength-(v*2)-o.scroll;
	            }
	            else if(to>=itemLength-v+1)
	            { // If last, then goto first
	                ul.css(animCss, -( (v) * liSize ) + "px" );
	                // If "scroll" > 1, then the "to" might not be equal to the condition; it can be greater depending on the number of elements.
	                curr = to==itemLength-v+1 ? v+1 : v+o.scroll;
	            }
	            else
	            {
	            	curr = to;
	            }
	        }
	        else
	        {                    // If non-circular and to points to first or last, we just return.
	        	if(v > itemLength)
	        	{
	        		curr = 0;
	        		o.speed = 0;
	        	}
	            else if(to<0 || to>itemLength-v)
	            {
	            	return;
	            }
	            else
	            {
	            	curr = to;
	            }
	        }                           // If neither overrides it, the curr will still be "to" and we can proceed.
	        
	        running = true;
	        
	        ul.animate(
	            animCss == "left" ? { left: -(curr*liSize) } : { top: -(curr*liSize) } , o.speed, o.easing,
	            function()
	            {
	                if(o.afterEnd)
	                {
	                    o.afterEnd.call(this, vis());
	                }
		        	if(v > itemLength)
		        	{
		        		o.speed = prevSpeed;
		        	}
	                running = false;
	            }
	        );
	        // Disable buttons when the carousel reaches the last/first, and enable when not
	        if(!o.circular)
	        {
	            $(o.btnPrev + "," + o.btnNext).removeClass("disabled");
	            if(v > itemLength)
	            {
	            	$(o.btnPrev + "," + o.btnNext).addClass("disabled");
	            }
	            else
	            {
		            $( (curr-o.scroll<0 && o.btnPrev)
		                ||
		               (curr+o.scroll > itemLength-v && o.btnNext)
		                ||
		               []
		             ).addClass("disabled");
	            }
	        }
	    }
	    return false;
	};
	
	function css(el, prop)
	{
	    return parseInt($.css(el[0], prop)) || 0;
	};
	
	function width(el)
	{
	    return  el[0].offsetWidth + css(el, 'marginLeft') + css(el, 'marginRight');
	};
	
	function height(el)
	{
	    return el[0].offsetHeight + css(el, 'marginTop') + css(el, 'marginBottom');
	};
		        
    function checkItems()
    {
    	var $li = $("li:visible", ul);
    	var move = false;
    	
    	if(itemLength > $li.size())
    	{
    		move = true;
    	}
    	
    	itemLength = $li.size();
        liSize = o.vertical ? height(li) : width(li);   // Full li size(incl margin)-Used for animation
        ulSize = liSize * itemLength;                   // size of full ul(total length, not just for the visible items)
        divSize = liSize * v;                           // size of entire div(total length for just the visible items)
        
        if(move)
        {
    		//go($li.size() - v, true);
        }
        
        // Disable buttons when the carousel reaches the last/first, and enable when not
        
        if(!o.circular)
        {
            if (curr-o.scroll <= itemLength-v){
            	$(o.btnPrev + "," + o.btnNext).removeClass("disabled");
            }        	
            if (curr-o.scroll<0 && o.btnPrev){
              $(o.btnPrev).addClass("disabled");
            }
            if ((curr+o.scroll > itemLength-v) || (itemLength-v === 0) && o.btnNext){
              $(o.btnNext).addClass("disabled");
            }
        }
    };
    
    var running = false;
    var animCss, sizeCss;
    var div, ul, tLi, tl, v;
    var li, itemLength, curr;
    var liSize;
    var ulSize;
    var divSize;
    var o;
	var methods = {
		init: function(opt)
		{
		    o = $.extend({
		        btnPrev: null,
		        btnNext: null,
		        btnGo: null,
		        mouseWheel: false,
		        auto: null,
		        
		        speed: 200,
		        easing: null,
		        
		        vertical: false,
		        circular: true,
		        visible: 3,
		        start: 0,
		        scroll: 1,
		        
		        beforeStart: null,
		        afterEnd: null,
		        
		        interval: null
		    }, opt || {});
		    return this.each(
		    	function()
		    	{                           // Returns the element collection. Chainable.
			        animCss=o.vertical?"top":"left"; sizeCss=o.vertical?"height":"width";
			        div = $(this); ul = $("ul", div); tLi = $("li", ul); tl = tLi.size(); v = o.visible;
			        
			        if(o.circular) {
			            ul.prepend(tLi.slice(tl-v-1+1).clone())
			              .append(tLi.slice(0,v).clone());
			            o.start += v;
			        }
			        
			        li = $("li", ul); itemLength = li.size(); curr = o.start;
			        div.css("visibility", "visible");
			        
			        li.css({overflow: "hidden", float: o.vertical ? "none" : "left"});
			        ul.css({margin: "0", padding: "0", position: "relative", "list-style-type": "none", "z-index": "1"});
			        div.css({overflow: "hidden", position: "relative", "z-index": "2", left: "0px"});
			        
			        liSize = o.vertical ? height(li) : width(li);   // Full li size(incl margin)-Used for animation
			        ulSize = liSize * itemLength;                   // size of full ul(total length, not just for the visible items)
			        divSize = liSize * v;                           // size of entire div(total length for just the visible items)
			        
			        li.css({width: li.width(), height: li.height()});
			        ul.css(sizeCss, ulSize+"px").css(animCss, -(curr*liSize));
			        
			        div.css(sizeCss, divSize+"px");                     // Width of the DIV. length of visible images
			        
			        // if not circular and number of items equal visible items, disable all arrows
			        if (!o.circular) {
			        	if (v >= itemLength){
			        		$(o.btnPrev + "," + o.btnNext).addClass("disabled");
			        	}
			        	else if ($.browser.msie && $.browser.version.substr(0,1)<7){ // IE6 bugfix
				        	$(o.btnNext).hide();
					        $(o.btnNext).show();
				        }
			        }
			        else if ($.browser.msie && $.browser.version.substr(0,1)<7){ // IE6 bugfix
			        	$(o.btnNext).hide();
				        $(o.btnNext).show();
			        }
			        
			        if(o.btnPrev)
			        {
			            $(o.btnPrev).click(function() {
			                if(o.interval){
			                    clearInterval(o.interval);
			                    o.interval = setInterval(function() {
			                        go(curr + o.scroll);
			                    }, o.auto+o.speed);
			                }
			                
			                return go(curr-o.scroll);
			            });
			        }
			        
			        if(o.btnNext)
			        {
			            $(o.btnNext).click(function() {
			                if(o.interval){
			                    clearInterval(o.interval);
			                    o.interval = setInterval(function() {
			                        go(curr + o.scroll);
			                    }, o.auto+o.speed);
			                }
			                
			                return go(curr+o.scroll);
			            });
			        }
			        
			        if(o.btnGo)
			        {
			            $.each(o.btnGo, function(i, val) {
			                $(val).click(function() {
			                    return go(o.circular ? o.visible+i : i);
			                });
			            });
			        }
			        
			        if(o.mouseWheel && div.mousewheel)
			        {
			            div.mousewheel(function(e, d) {
			                return d>0 ? go(curr-o.scroll) : go(curr+o.scroll);
			            });
			        }
			        
			        if(o.auto)
			        {
			            o.interval = setInterval(function() {
			                go(curr+o.scroll);
			            }, o.auto+o.speed);
			        }
		    	}
		    );
		},
		update: function(content)
		{
			checkItems();
			return this;
		},
		gotoBeginning: function ()
		{
			go(0);
			return this;
		}
	};
	
	$.fn.jkCarousel = function(method)
	{
		// Method calling logic
		if(methods[method])
		{
			return methods[ method ].apply(this, Array.prototype.slice.call( arguments, 1 ));
		}
		else if (typeof method === 'object' || ! method)
		{
			return methods.init.apply(this, arguments);
		}
		else
		{
			$.error( 'Method ' +  method + ' does not exist on jQuery.jkCarousel' );
		}
	};
}
)( jQuery );