Показать правильное миниатюрное изображение во всплывающем окне

У вас неправильный код... это мой код:

Живое демо на JSFiddle

Демонстрация 2 — Кнопка "Далее/Предыдущее"

HTML

<div id='gallery'>
    <div class='imgwrapper'>
        <img src='http://8pic.ir/images/6s75jpffwom32fhct7q4.jpg' title='' alt=''/>
        <span class='date'>15-02-2013</span>
        <span class='info'>This is the caption of the image along with some other information</span>
        <a href='http://gah-blog.blogspot.com/'>download</a>
    </div>
    <div class='imgwrapper'>
        <img src='http://8pic.ir/images/ypzla17xaqmhjiocih64.jpg' title='' alt=''/>
        <span class='date'>10-07-2013</span>
        <span class='info'>This is the caption of the image along with some other information</span>
        <a href='http://gah-blog.blogspot.com/'>download</a>
    </div>
    <div class='imgwrapper'>
        <img src='http://8pic.ir/images/tuwvju35ajgts0rxzufw.jpg' title='' alt=''/>
        <span class='date'>21-10-2013</span>
        <span class='info'>This is the caption of the image along with some other information</span>
        <a href='http://gah-blog.blogspot.com/'>download</a>
    </div>
    <div class='imgwrapper'>
        <img src='http://8pic.ir/images/usra1shyel8nxudsj8vs.jpg' title='' alt=''/>
        <span class='date'>02-02-2014</span>
        <span class='info'>This is the caption of the image along with some other information</span>
        <a href='http://gah-blog.blogspot.com/'>download</a>
    </div>
    <div class='imgwrapper'>
        <img src='http://8pic.ir/images/vp7wnu7ohpx2i3im6nem.jpg' title='' alt=''/>
        <span class='date'>20-05-2014</span>
        <span class='info'>This is the caption of the image along with some other information</span>
        <a href='http://gah-blog.blogspot.com/'>download</a>
    </div>
</div>


<div id="popupbg">
    <div id="popup">
        <img src='' title='' alt=''/>
        <span class='date'></span>
        <span class='info'></span>
        <a href=''>download</a>
        <span class="btn" id="close">Close</span>
    </div>

</div>

CSS

#gallery{
    position:relative;
    width:100%;
    background:#e7e7e7;
}
.imgwrapper{
    position:relative;
    width:150px;
    height:150px;
    display:inline-block;
}
.imgwrapper img{
    width:150px;
    height:150px;
}
.imgwrapper span,.imgwrapper a{
    display:none;
}
#popupbg{
    display:none;
    position:fixed;
    top:0;
    left:0;
    height:100%;
    width:100%;
    background:rgba(0,0,0,0.92);
    z-index:1000;
}
#popup{
    position:relative;
    top:5%;
    margin:0 auto;
    font-size:17px;
    width:70%;
    height:65%;
    background:#fff;
    padding:20px;
    border:solid 10px #CCCCCC;
}
#popup img{
    position:relative;
    display:block;
    width:95%;
    height:200px;
}
#popup span.date,#popup span.info,#popup span#close{
    display:block;
}

JQuery

$(document).ready(function(e) {
    $(".imgwrapper").click(function(){
        var img=$(' > img', this).attr("src");
        var date=$(' > span.date', this).html();
        var info=$(' > span.info', this).html();
        var a=$(' > a', this).attr("href");

        $('#popup img').attr("src",img);
        $('#popup span.date').html(date);
        $('#popup span.info').html(info);
        $('#popup a').attr("href",a);

        user_guide()
    });
});

function user_guide(){
    $("#popupbg").fadeToggle("slow");
}

$(document).ready(function(e) {
    $("#close").click(function(){
        $("#popupbg").fadeToggle("slow");
    });
});