Question

Below I use the id of a clicked item to tell my function which <div> to animate.

However it never seems to animate….

Basically you click and <img> and it uses the ID of that image previewItem to tell what <div> to animate. '#p + previewItem'

<script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
<script type="text/javascript" src="jquery.easing.1.2.js" ></script> 

<script type="text/javascript">
<!--

    $(document).ready(function()
    {
        var previewItem;

        $(this).click(function(event) {
            //get the ID of the clicked area
            previewItem = event.target.id;

            //alert("#p" + previewItem);
            $("#p" + previewItem).animate({left:"50%"},{duration: 3000,easing: easeOutBounce});

            //alert(previewItem);
        });
    });

    // wrap as a jQuery plugin and pass jQuery in to our anoymous function
    (function ($) {
        $.fn.cross = function (options) {
            return this.each(function (i) { 
                // cache the copy of jQuery(this) - the start image
                var $$ = $(this);

                // get the target from the backgroundImage + regexp
                var target = $$.css('backgroundImage').replace(/^url|[\(\)'"]/g, '');

                // nice long chain: wrap img element in span
                $$.wrap('<span style="position: relative;"></span>')
                    // change selector to parent - i.e. newly created span
                    .parent()
                    // prepend a new image inside the span
                    .prepend('<img>')
                    // change the selector to the newly created image
                    .find(':first-child')
                    // set the image to the target
                    .attr('src', target);

                // the CSS styling of the start image needs to be handled
                // differently for different browsers
                if ($.browser.msie || $.browser.mozilla) {
                    $$.css({
                        'position' : 'absolute', 
                        'left' : 0,
                        'background' : '',
                        'top' : this.offsetTop
                    });
                } else if ($.browser.opera && $.browser.version < 9.5) {
                    // Browser sniffing is bad - however opera < 9.5 has a render bug 
                    // so this is required to get around it we can't apply the 'top' : 0 
                    // separately because Mozilla strips the style set originally somehow...                    
                    $$.css({
                        'position' : 'absolute', 
                        'left' : 0,
                        'background' : '',
                        'top' : "0"
                    });
                } else { // Safari
                    $$.css({
                        'position' : 'absolute', 
                        'left' : 0,
                        'background' : ''
                    });
                }

                // similar effect as single image technique, except using .animate 
                // which will handle the fading up from the right opacity for us
                $$.hover(function () {
                    $$.stop().animate({
                        opacity: 0
                    }, 250);
                }, function () {
                    $$.stop().animate({
                        opacity: 1
                    }, 2000);
                });
            });
        };

    })(jQuery);

    // note that this uses the .bind('load') on the window object, rather than $(document).ready() 
    // because .ready() fires before the images have loaded, but we need to fire *after* because
    // our code relies on the dimensions of the images already in place.
    $(window).bind('load', function () {
        $('img.fade').cross();
    });

//-->
</script>

Answer 1

While the other answers are also correct, if you’re using the jquery easing plugin (found at http://gsgd.co.uk/sandbox/jquery/easing/), you should take note that the easing option is a string.

So your call would be:

$("#p" + previewItem).animate({left:"50%"},{duration: 3000,easing: 'easeOutBounce'});