Jquery下一个按钮不能与图片库一起工作

Question

在我点击下一个按钮'两次'后，大图只会变成下一张图片。它适用于上一个按钮，但无论何时重新加载页面，下一个按钮都不行。

如果你能看看问题是什么，那将是很好的，因为我已经尝试了很长时间来修复它，但是不能。先谢谢你。

<div > 
    <table id = "frame-table"> 
    <tr> 
     <td id = "left1"> 
     <img src="http://www.vintagevictorian.com/kuba_arrow_button_left.png" alt = "left"/> 
     </td> 
     <td id = "right1"> 
     <img src="http://4vector.com/i/free-vector-kuba-arrow-button-set-clip-art_117492_Kuba_Arrow_Button_Set_clip_art_hight.png" alt = "right"/> 
     </td> 
    </tr> 
    </table> 
    <img class="img" src="http://www.gravatar.com/avatar/3d561d41394ff0d5d0715b2695c3dcf0?s=128&d=identicon&r=PG" alt="Chania" width="204" height="236"> 
</div> 

<div id = "wrapper"> 
    <ul id = "portfolio"> 
    <li><img class="img-thumbnail" src="http://www.gravatar.com/avatar/3d561d41394ff0d5d0715b2695c3dcf0?s=128&d=identicon&r=PG" alt = "img"/></li> 
    <li><img class="img-thumbnail" src="http://upload.wikimedia.org/wikipedia/commons/thumb/8/85/Smiley.svg/2000px-Smiley.svg.png" alt = "img"/></li> 
    <li><img class="img-thumbnail" src="https://lh3.googleusercontent.com/-JE-Vccj5xwk/AAAAAAAAAAI/AAAAAAAAABg/aFghGr0aeYw/photo.jpg" alt = "img"/></li> 
    </ul> 
    <button id="zoom" type="button" class="btn btn-info"> 
    <span class="glyphicon glyphicon-search"> Zoom </span> 
    </button> 
</div> 

$(function(){ 
    var current_li =$("#portfolio li").first().parent(); 
    $("#right1").click(function(){ 
    if (current_li.is(":last-child")){ 
     var next_li = $("#portfolio li").first(); 
    } else{ 
     var next_li = current_li.next(); 
    } 

    var next_src = next_li.children("img").attr("src"); 
    alert(next_src); 
    $(".img").attr("src", next_src); 
    current_li = next_li; 
    }); 

    $("#left1").click(function(){ 
    if (current_li.is(":first-child")){ 
     var prev_li = $("#portfolio li").last(); 
    } else{ 
     var prev_li = current_li.prev(); 
    } 
    var prev_src = prev_li.children("img").attr("src"); 
    $(".img").attr("src", prev_src); 
    current_li = prev_li; 
    }); 
}); 

Answer 1

var current_li =$("#portfolio li").first().parent(); 

应该

var current_li =$("#portfolio>li").first(); 

本地测试，是工作。