diff --git a/app/helpers/watchers_helper.rb b/app/helpers/watchers_helper.rb
index 298331c69..6d916f43e 100644
--- a/app/helpers/watchers_helper.rb
+++ b/app/helpers/watchers_helper.rb
@@ -97,7 +97,7 @@ module WatchersHelper
     return '' unless user && user.logged?
     # modify by nwb
     # 主讲教师不允许退出课程
-    return '' if user.id == course.tea_id || course.is_public == 0
+    return '' if user.id == course.tea_id
     joined = user.member_of_course?(course)
     text = joined ? l(:label_exit_course) : l(:label_new_join)
     url_t = join_path(:object_id => course.id)
diff --git a/app/views/courses/_course_ad.html.erb b/app/views/courses/_course_ad.html.erb
index 10a6d7eaf..f8b4781f8 100644
--- a/app/views/courses/_course_ad.html.erb
+++ b/app/views/courses/_course_ad.html.erb
@@ -1,6 +1,6 @@
 
 <div id="floatpoint" class="course_ad"  >
-  <table  border=0 width="180px" >
+  <table  border=0>
     <tr>
       <td align=center bgcolor=#15bccf >
        <span class="ad_title"><%= l(:label_contact_us) %></span> 
@@ -30,85 +30,26 @@
 </div>
 
 <script type="text/javascript">
-    var XX=1150;			// 浮动层的X坐标,即左边距
     var xstep=1;			// 移动步长，此参数越小，移动越平滑，最小值为1
     var delay_time=60;		// 每步的时间间隔，此参数越小，移动速度越快
     var YY=0;
-    var ch=0;
-    var oh=0;
-    var yon=1;
-    var ns4=document.layers?1:0
-    var ie=document.all?1:0
-    var ns6=document.getElementById&&!document.all?1:0
+    var screen_height = $(window).height();          //浏览器当前窗口文档的高度
+    var screen_width = $(window).width();            //浏览器当前窗口文档的宽度
 
-    if(ie){
-        YY=document.body.clientHeight;				//由clientHeight取得页面的高度
-        floatpoint.style.top=YY;				//将浮动层位置调整到页面底部
-    }
-    else if (ns4){
-
-        YY=window.innerHeight;					//由innerHeight取得页面的高度
-        document.floatpoint.pageY=YY;				//将浮动层位置调整到页面底部
-        document.floatpoint.visibility="hidden";		//将浮动层隐藏。
-    }
-    else if (ns6){
-
-        YY=window.innerHeight					//由innerHeight取得页面的高度
-        document.getElementById('floatpoint').style.top=YY	//将浮动层位置调整到页面底部
-    }
-    YY = 0;
-    function reloc1(){
-        if (ie){
-            ch=document.body.clientHeight;
-            oh=floatpoint.offsetHeight;
-        }
-        else if (ns4){
-            ch=window.innerHeight;
-            oh=document.floatpoint.clip.height;
-        }
-        else if (ns6){						//如果是NS6
-            ch=window.innerHeight					//取页面高度
-            oh=document.getElementById("floatpoint").offsetHeight	//取浮动层的高度
-        }
-
-        if(yon==0)
-        {
-            YY=YY-xstep;
-        }				//如果当前应该上移，则减小YY值
-        else
-        {
-            YY=YY+xstep;
-        }					//否则增加YY值下移
-        if(YY<0){yon=1;YY=0;}					//如果浮动层超出了上界，则设定移动方向为向下；并设定层的位置为正好在上界处
-        if(YY>=(ch-oh)){yon=0;YY=(ch-oh);}			//如果浮动层超出了下界，则设定移动方向为向上；并设定层的位置为正好在下界处
-        if(ie){							//如果是IE
-            floatpoint.style.left=XX;				//用style.left设定浮动层左边距
-            floatpoint.style.top=YY+document.body.scrollTop;	//用style.top设定浮动层上边距
-        }
-        else if (ns4){						//如果是NS4
-            document.floatpoint.pageX=XX;				//用.pageX设定浮动层左边距
-            document.floatpoint.pageY=YY+window.pageYOffset;	//用.pageY设定浮动层上边距
-        }
-        else if (ns6){						//如果是NS6
-//            document.getElementById("floatpoint").style.left=XX
-//            document.getElementById("floatpoint").style.top=YY+window.pageYOffset
-            $("#floatpoint").offset({left:XX});
-            $("#floatpoint").offset({top:YY+window.pageYOffset});
-        }
-
-    }
-
-    function onad(){
-
-        if(ns4)			//如果是NS4
-            document.floatpoint.visibility="visible";		//设定浮动层为可见
-        loopfunc();						//开始主循环，以不断改变浮动层位置
-    }
-    function loopfunc(){
-        reloc1();						//调整浮动层位置
-        setTimeout('loopfunc()',delay_time);			//设定下一次调整的延时
-    }
-    if (ie||ns4||ns6)
-        //window.onload=onad					//初始化事件触发器
-        $(document).ready(onad());
+   window.setInterval(function(){move();},delay_time);
+   function move()
+   {
+       var floatpoint_height = $("#floatpoint").height();
+       YY += xstep;
+       if(YY <= 0){xstep = 1; YY = 0;}					//如果浮动层超出了上界，则设定移动方向为向下；并设定层的位置为正好在上界处
+       if(YY >= (screen_height-floatpoint_height))      //如果浮动层超出了下界，则设定移动方向为向上；并设定层的位置为正好在下界处
+       {
+           xstep = -1;
+           YY=(screen_height-floatpoint_height);
+       }
+       $("#floatpoint").css("top",YY);
+   }
+   function change_size(){var body_width = $("#top-menu").width(); $("#floatpoint").css("left",screen_width/2+body_width/2+10);}
+   $(document).ready(function(){change_size();});
+   $(window).resize(function(){screen_width = $(window).width();change_size();});
 </script>
\ No newline at end of file
diff --git a/app/views/courses/homework.html.erb b/app/views/courses/homework.html.erb
index 95e26abd0..68ec0dc2e 100644
--- a/app/views/courses/homework.html.erb
+++ b/app/views/courses/homework.html.erb
@@ -5,11 +5,12 @@
 </style>
 <%= javascript_include_tag 'attachments' %>
 <!-- fq -->
-<!--modified by huang-->
 <div class="content-title-top">
-	<% if User.current.logged? && (User.current.admin? || (!Member.where('user_id = ? and course_id = ?', User.current.id, @course.id).first.nil? && (Member.where('user_id = ? and course_id = ?', User.current.id, @course.id).first.roles&Role.where(id: [3, 4, 7, 9] )).size >0))%>
-		<%= link_to(l(:label_course_homework_new), {:controller => 'courses', :action => 'new_homework'}, :class => 'icon icon-add') %>
-	<% end %>
+  <% if User.current.logged? && (User.current.admin? || (!Member.where('user_id = ? and course_id = ?', User.current.id, @course.id).first.nil? && (Member.where('user_id = ? and course_id = ?', User.current.id, @course.id).first.roles&Role.where(id: [3, 4, 7, 9] )).size >0))%>
+    <%= link_to(l(:label_course_homework_new), {:controller => 'courses', :action => 'new_homework'}, :class => 'icon icon-add') %>
+  <% else %>
+	<span class="font_lighter"><%= l(:label_coursejoin_tip) %></span>
+  <% end %>
 </div>
 <div id="bid-show">
 	<%= render :partial => 'bids/bid_homework_show', :locals => {:bids => @bids, :bid_pages => @bid_pages} %>
diff --git a/app/views/files/_course_file.html.erb b/app/views/files/_course_file.html.erb
index c48900426..46a954746 100644
--- a/app/views/files/_course_file.html.erb
+++ b/app/views/files/_course_file.html.erb
@@ -13,7 +13,37 @@
     <%= link_to(l(:label_upload_files), 'javascript:void(0);', :class => 'icon m5p5 button_submit', :onclick => "$('#relation_file_div').slideUp();$('#upload_file_div').slideToggle('slow');") if User.current.allowed_to?(:manage_files, @course) %>
     <%= link_to(l(:label_relation_files), 'javascript:void(0);', :onclick => "$('#upload_file_div').slideUp();$('#relation_file_div').slideToggle();", :class => 'icon m5p5 button_submit') if User.current.allowed_to?(:manage_files, @course) %>
     <p></p>
+    <div id="upload_file_div" class="relation_file_div hidden">
+      <%= render :partial => 'course_new', locals: {course: @course} %>
+    </div>
 
+    <div id="relation_file_div" class="relation_file_div hidden">
+      <fieldset>
+        <legend>搜索</legend>
+        <%= form_tag(
+                    attachments_autocomplete_path(:format => 'js'),
+                    :remote => true,
+                    :method => :post) do %>
+            <%= label_tag(:attach_search, "按关键字搜索:") %>
+            <%= text_field_tag(:attach_search) %>
+            <%#= submit_tag("Search") %>
+        <% end -%>
+        <%= form_tag course_attach_relation_path(:format => 'js'),
+                     method: :post,
+                     remote: true,
+                     id: "relation_file_form",
+                     :class => 'hidden' do %>
+            <%= hidden_field_tag(:class_name, 'course') %>
+            <%= hidden_field_tag(:class_id, params[:course_id]) %>
+            <div id="relation_file">
+            </div>
+            <div class="kclearfix" style='margin-top: 10px;'>
+              <%= submit_tag(l(:button_add)) -%>
+            </div>
+        <% end -%>
+      </fieldset>
+      <div class="line_under" style="margin:20px 0px;"></div>
+    </div>
 
   </div>
   <div class="box" id="files-box">
diff --git a/app/views/files/_course_new.html.erb b/app/views/files/_course_new.html.erb
index f864f8629..2eaa70cb6 100644
--- a/app/views/files/_course_new.html.erb
+++ b/app/views/files/_course_new.html.erb
@@ -20,28 +20,6 @@
 <% end %>
 <div class="line_under" style="margin:20px 0px;"></div>
 
-
-  <fieldset>
-	<legend><%=l(:label_attachment_new)%></legend>
-		<% attachmenttypes = course.attachmenttypes %>
-		<%= error_messages_for 'attachment' %>
-		<%= form_tag(course_files_path(course), :multipart => true,:remote => true,:method => :post,:name=>"upload_form", :class => "tabular") do %>
-	
-		  <p>
-		    <% if attachmenttypes.any? %>
-		        <%= l(:attachment_type) %></label>
-		        <%= select_tag "attachment_type",
-		                       options_from_collection_for_select(attachmenttypes, "id",
-		                                                          "typeName", 2), {style: 'width:100px'} %>
-		   <% end %>
-		  </p>
-		
-		<p><%=l(:label_attachment_plural)%></label><%= render :partial => 'attachments/form' %></p>
-	
-		<%= submit_tag l(:button_add) %>
-		<% end %>
-   </fieldset>
-
 <script type='text/javascript'>
     function tagAddClick(id,objId,objTag)
     {
diff --git a/config/locales/zh.yml b/config/locales/zh.yml
index 0220a10e5..a3807dca3 100644
--- a/config/locales/zh.yml
+++ b/config/locales/zh.yml
@@ -2134,6 +2134,7 @@ zh:
   label_notification: 通知公告
   label_course_ad_description: 课程模块正在优化中，使用过程中如有问题请您与我们联系，感谢大家的支持！
   label_course_adcolick: 请点击：
+  label_coursejoin_tip: 提示：加入课程才有权限查看或提交作业，“加入”按钮见课程图标右侧！
   #end  
 
   #end
diff --git a/public/stylesheets/application.css b/public/stylesheets/application.css
index 710a404dc..ad947dcde 100644
--- a/public/stylesheets/application.css
+++ b/public/stylesheets/application.css
@@ -12,7 +12,8 @@ h4 {border-bottom: 1px dotted #bbb;}
 .course_ad{
   position:absolute;
   visibility:visible;
-  background:#ffffff
+  background:#ffffff;
+  width:14%;
 }
 
 .ad_title{