[рони]

Alex1233,

$(document).ready(function () {
    var timer;
    $("#list_wrap").on("mouseenter", ".list_box", function () {
        clearTimeout(timer)
       var $dem = $(this).find('img');
        $dem.stop();
        var $startWidth = $dem.width();
        var $startHeight = $dem.height();
        var $origWidth = $dem.attr('width');
        var $origHeight = $dem.attr('orh');
        $origWidth < $startWidth && ($origWidth = $startWidth * 1.2);
        $origHeight < $startHeight && ($origHeight = $startHeight * 1.2);
        $sdvigLeft = (($origWidth - $startWidth) / 2) * (-1);
        $sdvigTop = (($origHeight - $startHeight) / 2) * (-1);
        timer = setTimeout(function () {
            $dem.animate({
                'marginLeft': $sdvigLeft + 'px',
                'marginTop': $sdvigTop + 'px',
                'width': $origWidth + 'px',
                'position': 'absolute',
                'maxWidth': '900px'
            }, 100);
        }, 500);
    }).on('mouseleave', '.list_box', function () {
        clearTimeout(timer)
        $(this).find('img').stop().css({
            'marginLeft': '0',
            'marginTop': '0',
            'width': '310px',
            'position': 'absolute',
            'maxWidth': '100%'
        });
    });
});