实训项目图片问题

app/views/admins/laboratory_settings/show.html.erb

@@ -104,7 +104,7 @@
           <%- shixun_banner = setting.shixun_banner_url -%>
           <div class="banner-item-top">实训项目</div>
           <div class="banner-item-bottom <%= shixun_banner ? 'has-img' : '' %>">
-            <img class="banner-item-img shixun-banner-img" src="<%= shixun_banner %>" style="<%= subject_banner.present? ? '' : 'display: none' %>"/>
+            <img class="banner-item-img shixun-banner-img" src="<%= shixun_banner %>" style="<%= shixun_banner.present? ? '' : 'display: none' %>"/>
             <%= file_field_tag(:shixun_banner, accept: 'image/*', style: 'display: none', value: params[:shixun_banner]) %>
             <label for="shixun_banner" class="banner-item-upload" data-toggle="tooltip" data-title="选择图片"></label>
           </div>