一个html和js的幻灯片，怎么大图不显示，只有缩略图，如下图所示

山中习静观朝槿 2017-10-13 04:28:17

代码如下有点长，希望大神指出问题，谢谢
css：
.slider,
.slider .main,
.slider .main .main-i{
width:100%;
height:400px;
/*用relative方便元素定位*/
position:relative;
top:50px;
}

/*幻灯片区域*/
.slider .main{
overflow:hidden;/**/
}
/*幻灯片区域样式*/
.slider .main .main-i img{
width:100%;
/*图片漂浮*/
position:absolute;
left:0;
z-index:1;
}
.slider .main .main-i .caption{
/*标题漂浮*/
position:absolute;
left:10%;
top:30%;
/*使caption标题悬浮于图片上*/
z-index:2;
}
.slider .main .main-i .caption h2{
font-size:50px;
line-height :50px;
color:#B5B5B5;
text-align:left;
}
.slider .main .main-i .caption h3{
font-size:30px;
line-height :30px;
color:#000000;
text-align:left;
font-family:'Open Sans Condensed';
}
/*控制按钮样式*/
.slider .ctrl{
top:450px;
width:100%;
height:13px;
line-height:13px;
/*控制按钮水平居中*/
text-align:center;
position:absolute;
bottom:13px;
}
.slider .ctrl .ctrl-i{
display:inline-block;
width:10%;
height:13px;
border:0;
background-color:#666;
/*让子元素的img可以进行定位*/
position:relative;
box-shadow:0 1px 1px rgba(0,0,0,0.3);
margin-left:1px;
}
.slider .ctrl .ctrl-i img{
width:100%;
position:absolute;
left:0;
bottom :50px;
z-index:1;
/*透明度为0，不显示*/
opacity:0;
-webkit-transition:all 0.3s;
}
/*hover到控制按钮的样式*/
.slider .ctrl .ctrl-i:hover{
background-color:#f0f0f0;
}
.slider .ctrl .ctrl-i:hover img{
bottom:13px;
/*鼠标移动后为1，显示*/
opacity :1;
}
/*active当前状态展现*/
.slider .ctrl .ctrl-i_active:hover,
.slider .ctrl .ctrl-i_active{
background-color:#000;
}
.slider .ctrl .ctrl-i_active:hover img{
opacity:0;
}
/*幻灯片切换的样式*/
.slider .main .main-i{
opacity:0;
position:absolute ;
top:50px;
-webkit-transition:all 0.5s;
}
.slider .main .main-i h2{
margin-right:45px;
}
.slider .main .main-i h3{
margin-right:-45px;
}
.slider .main .main-i h2,
.slider .main .main-i h3{
-webkit-transition:all 1s;
}
.slider .main .main-i_active{
opacity:1;
right:0;
}
.slider .main .main-i_active h2,
.slider .main .main-i_active h3{
margin-right:0px;
}

HTML和js：
<div class="slider">
<div class="main" id="template_main">
<div class="main-i" id="main_{{index}}">
<div class="caption">
<h2>{{h2}}</h2>
<h3>{{h3}}</h3>
</div>
<img src="image/{{index}}.jpg" />
</div>
</div>
<div class="ctrl" id="template_ctrl">
<a class="ctrl-i" id="ctrl_{{index}}" href="javascript:switchSlider({{index}});"><img src="image/{{index}}.jpg" /></a>
</div>

<script type="text/javascript">
//应当由ajax进行后台输出
var data = [
{ img: 1, h1: '111', h2: '222' },
{ img: 2, h1: '111', h2: '222' },
{ img: 3, h1: '111', h2: '222' },
{ img: 4, h1: '111', h2: '222' },
{ img: 5, h1: '111', h2: '222' }
];
//通用元素
var g = function (id) {
if (id.substr(0, 1) == '.') {
return document.getElementsByClassName(id.substr(1));
}
return document.getElementById(id);
}
//添加幻灯片
function addSliders() {
//获取模板
var tpl_main = g('template_main').innerHTML
.replace(/^\s*/, '')
.replace(/\s*$/, '');
var tpl_ctrl = g('template_ctrl').innerHTML
.replace(/^\s*/, '')
.replace(/\s*$/, '');
//定义最后输出的HTML变量
var out_main = [];
var out_ctrl = [];

for (i in data) {
var _html_main = tpl_main
.replace(/{{index}}/g, data[i].img)
.replace(/{{h2}}/g, data[i].h1)
.replace(/{{h3}}/g, data[i].h2);
var _html_ctrl = tpl_ctrl
.replace(/{{index}}/g, data[i].img);
out_main.push(_html_main);
out_ctrl.push(_html_ctrl);
}
//HTML回写到DOM中
g('template_main').innerHTML = out_main.join('');
g('template_ctrl').innerHTML = out_ctrl.join('');

}
//幻灯片切换
function switchSlider(n) {
var main = g('main' + n);
var ctrl = g('ctrl' + n);

var clear_main = g('main-i');
var clear_ctrl = g('ctrl-i');

for (i = 0; i < clear_ctrl.length; i++) {
clear_main[i].className = clear_main[i].className
.replace('main-i_active', '');
clear_ctrl[i].className = clear_ctrl[i].className
.replace('ctrl-i_active', '');
}

main.className += 'main-i_active';
ctrl.className += 'ctrl-i_active';
}
window.onload = function () {
addSliders();
switchSlider(1);
}
</script>
</div>

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