课程下的班级列表图片丢失

app/views/syllabuses/_syllabus_course_list.html.erb

@@ -75,7 +75,7 @@
       </div>
    </div>
 <% else %>
-    <div class="icons_tishi"><img src="../images/sy/icons_tan.png" width="110" height="110" alt="" ></div>
+    <div class="icons_tishi"><img src="/images/sy/icons_tan.png" width="110" height="110" alt="" ></div>
     <% if User.current == @syllabus.user %>
         <p class="sy_tab_con_p">您建立的课程还未创建班级，请
           <%= link_to "新建班级", new_course_path(:host=> Setting.host_course, :syllabus_id => @syllabus.id), :class => "sy_corange", :target => '_blank'%>