/**
* @extends jquery
*/

jQuery.fn.carousel = function (duration) {
    var sliderList = jQuery(this).children()[0];

    if (sliderList) {

        var increment = jQuery(sliderList).children().outerWidth("true"),
		elmnts = jQuery(sliderList).children(),
		numElmts = elmnts.length,
		sizeFirstElmnt = increment,
		shownInViewport = Math.round(jQuery(this).width() / sizeFirstElmnt),
		firstElementOnViewPort = 1,
		isAnimating = false;

        for (i = 0; i < shownInViewport; i++) {
            jQuery(sliderList).css('width', (numElmts + shownInViewport) * increment + increment + "px");
            jQuery(sliderList).append(jQuery(elmnts[i]).clone());
        }

        var goLeft = function () {

            if (firstElementOnViewPort > numElmts) {
                firstElementOnViewPort = 2;
                jQuery(sliderList).css('left', "0px");
            }
            else {
                firstElementOnViewPort++;
            }

            jQuery(sliderList).animate({
                left: "-=" + increment,
                queue: true,
                easing: 'linear'
            }, duration, function () {
                goLeft();

            });
        }
        goLeft();
    }
};