<input style="display:none" type="file" name="file" class="bannerupload" id="fileField" onchange="PreviewImage(this,'imgHeadPhoto','divPreview');" size="20" />
<input type='button' class="bannerupload" value='选择图片' onclick="document.getElementById('fileField').click()" />
<input type="submit" class="layui-btn" value="上传"/>
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.bannerupload{
display: inline-block;
height: 38px;
line-height: 9px;
padding: 0 18px;
background-color: #009688;
color: #fff;
white-space: nowrap;
text-align: center;
font-size: 14px;
border: none;
border-radius: 2px;
cursor: pointer;
}
.bannerchange{
position: absolute;
overflow: hidden;
right: 0;
top: 0;
opacity: 0;
}