diff --git a/app/controllers/exercise_controller.rb b/app/controllers/exercise_controller.rb
index 6066ef3d0..d4050da18 100644
--- a/app/controllers/exercise_controller.rb
+++ b/app/controllers/exercise_controller.rb
@@ -34,17 +34,24 @@ class ExerciseController < ApplicationController
       render_403
       return
     end
-    @can_edit_excercise = (!has_commit_exercise?(@exercise.id,User.current.id)) || User.current.admin?
+    exercise_end = Time.parse(format_time(@exercise.end_time)).strftime("%Y-%m-%d %H:%M:%S") > Time.now.strftime("%Y-%m-%d %H:%M:%S")
+    if @exercise.time == -1
+      @can_edit_excercise = exercise_end
+    else
+      @can_edit_excercise = (!has_commit_exercise?(@exercise.id,User.current.id)&& exercise_end) || User.current.admin?
+    end
     @exercise_user = ExerciseUser.where("user_id=? and exercise_id=?", User.current.id, @exercise.id).first
       # 学生点击的时候即创建关联,自动保存
       #eu = ExerciseUser.create(:user_id => User.current, :exercise_id => @exercise.id, :start_at => Time.now, :status => false)
 
     # 已提交问卷的用户不能再访问该界面
+=begin
     if has_commit_exercise?(@exercise.id, User.current.id) && (!User.current.admin?)
       respond_to do |format|
         format.html {render :layout => 'base_courses'}
       end
     else
+=end
       if !@is_teacher && !has_click_exercise?(@exercise.id, User.current.id)
         eu = ExerciseUser.create(:user_id => User.current.id, :exercise_id => @exercise.id, :start_at => Time.now, :status => false)
         @exercise_user = ExerciseUser.where("user_id=? and exercise_id=?", User.current.id, @exercise.id).first
@@ -55,7 +62,7 @@ class ExerciseController < ApplicationController
       respond_to do |format|
         format.html {render :layout => 'base_courses'}
       end
-    end
+    #end
   end
 
   def new
@@ -82,7 +89,7 @@ class ExerciseController < ApplicationController
       exercise ||= Exercise.new
       exercise.exercise_name = params[:exercise][:exercise_name]
       exercise.exercise_description = params[:exercise][:exercise_description]
-      exercise.end_time = params[:exercise][:end_time]
+      exercise.end_time = Time.at(params[:exercise][:end_time].to_time.to_i + 16*60*60 -1)
       exercise.publish_time = params[:exercise][:publish_time]
       exercise.user_id = User.current.id
       exercise.time = params[:exercise][:time]
@@ -107,7 +114,7 @@ class ExerciseController < ApplicationController
     @exercise.exercise_name = params[:exercise][:exercise_name]
     @exercise.exercise_description = params[:exercise][:exercise_description]
     @exercise.time =  params[:exercise][:time].blank? ? -1 : params[:exercise][:time]
-    @exercise.end_time = params[:exercise][:end_time]
+    @exercise.end_time = Time.at(params[:exercise][:end_time].to_time.to_i + 16*60*60 -1)
     @exercise.publish_time = params[:exercise][:publish_time]
     @exercise.show_result = params[:exercise][:show_result].blank? ? 1 : params[:exercise][:show_result]
     if @exercise.save
@@ -351,8 +358,8 @@ class ExerciseController < ApplicationController
   # 学生提交答卷，选中答案的过程中提交
   def commit_answer
     eq = ExerciseQuestion.find(params[:exercise_question_id])
-    # 已提交过的则不允许答题
-    if has_commit_exercise?(@exercise.id,User.current.id) && (!User.current.admin?)
+    # 已提交过的且是限时的则不允许答题
+    if has_commit_exercise?(@exercise.id,User.current.id) && (!User.current.admin?) && @exercise.time != -1
       render :json => {:text => "failure"}
       return
     end
diff --git a/app/views/exercise/_commit_alert.html.erb b/app/views/exercise/_commit_alert.html.erb
index d92ca51fb..a21dbd2a7 100644
--- a/app/views/exercise/_commit_alert.html.erb
+++ b/app/views/exercise/_commit_alert.html.erb
@@ -1,7 +1,10 @@
 <div id="popbox" style="text-align: center;margin-top: 25px">
-  <% if status == 0 %>
+  <% if status == 0 && exercise.time != -1 %>
       <h3 style="font-weight: normal;color: green">提交成功!您的分数是：<%=@score %>分。</h3>
       <%= link_to "确定", exercise_path(),:class => 'commit'%>
+  <% elsif status == 0 && Time.parse(format_time(exercise.end_time)).strftime("%Y-%m-%d %H:%M:%S") > Time.now.strftime("%Y-%m-%d %H:%M:%S") %>
+      <h3 style="font-weight: normal;color: green">提交成功!</h3>
+      <%= link_to "确定", exercise_index_path(:course_id => @course.id),:class => 'commit'%>
   <% elsif status == 1 %>
       <h3 style="font-weight: normal;color: red">您还有尚未作答的题目请完成后再提交!</h3>
       <%= link_to "确定", "javascript:void(0)",:onclick => 'hidden_atert_form();',:class => 'commit'%>
diff --git a/app/views/exercise/_exercise.html.erb b/app/views/exercise/_exercise.html.erb
index 91af83aee..db412672c 100644
--- a/app/views/exercise/_exercise.html.erb
+++ b/app/views/exercise/_exercise.html.erb
@@ -53,7 +53,7 @@
             <!--li><%#= link_to poll_name, poll_result_poll_path(poll.id), :class => "polls_title polls_title_st fl c_dblue" %></li>
             <li class="pollsbtn_tip fl ml5">已答</li-->
         <%#else%>
-            <%= link_to exercise_name, exercise_path(exercise.id), :class => "polls_title polls_title_st fl c_dblue"%>
+            <%= link_to (index.to_i+1).to_s+". "+exercise_name, exercise_path(exercise.id), :class => "polls_title polls_title_st fl c_dblue"%>
         <%#end%>
     <% end%>
     <li class="polls_date fr mr10">截止时间：<%= format_time(exercise.end_time.to_s)%></li>
diff --git a/app/views/exercise/_exercise_form.html.erb b/app/views/exercise/_exercise_form.html.erb
index 8de4dac38..e283f8b0c 100644
--- a/app/views/exercise/_exercise_form.html.erb
+++ b/app/views/exercise/_exercise_form.html.erb
@@ -136,14 +136,14 @@
             alert("测验标题不能为空");
         } else if($.trim($("#exercise_end_time").val()) =="") {
             alert("截止时间不能为空");
-        } else if(Date.parse($("#exercise_end_time").val()) < Date.now()) {
+        } else if((Date.parse($("#exercise_end_time").val())+(24*60*60-1)*1000) < Date.now()) {
             alert("截止时间不能小于当前时间");
         } else if($.trim($("#exercise_time").val()) !="" && !/^[1-9][0-9]*$/.test($.trim($("#exercise_time").val()))) {
             alert("测验时长必须为非零开头的数字");
         } else if($.trim($("#exercise_publish_time").val()) !="" && Date.parse($("#exercise_publish_time").val()) < Date.now()) {
             alert("发布时间不能小于当前时间");
-        } else if($.trim($("#exercise_publish_time").val()) !="" && Date.parse($("#exercise_end_time").val()) <= Date.parse($("#exercise_publish_time").val())) {
-            alert("截止时间必须大于发布时间");
+        } else if($.trim($("#exercise_publish_time").val()) !="" && Date.parse($("#exercise_end_time").val()) < Date.parse($("#exercise_publish_time").val())) {
+            alert("截止时间不能小于发布时间");
         } else {
             doc.parent().parent().parent().submit();
         }
diff --git a/app/views/exercise/_exercise_student.html.erb b/app/views/exercise/_exercise_student.html.erb
index 20b8a3d8c..7010407ce 100644
--- a/app/views/exercise/_exercise_student.html.erb
+++ b/app/views/exercise/_exercise_student.html.erb
@@ -3,6 +3,8 @@
         $("#RSide").removeAttr("id");
         $("#homework_page_right").css("min-height",$("#LSide").height()-30);
         $("#Container").css("width","1000px");
+        end_time = <%=exercise.end_time.to_i%>
+        getTime(end_time);
         /*start_time = new Date();
         start_time.setFullYear(<%#=exercise_user.start_at.year%>);
         start_time.setMonth(<%#=exercise_user.start_at.month%>);
@@ -17,11 +19,16 @@
     function getTime(end_time) {
         //alert(end_time);
         now = new Date();
-        var total_seconds = (now.getTime() - end_time)/1000;
+        var total_seconds = now.getTime()/1000 - end_time;
+        if (total_seconds < 0) {
+            $("#exercise_submit_btn").click();
+            return;
+        }
+        setTimeout("getTime("+end_time+");", 1000);
         //start = new Date(start_time);
         //end_time = start_time;
         //var total_seconds = total_seconds - 1;
-        var hours = total_seconds / 60 / 60;
+        /*var hours = total_seconds / 60 / 60;
         var hoursRound = Math.floor(hours);
         var minutes = total_seconds /60 - (60 * hoursRound);
         var minutesRound = Math.floor(minutes);
@@ -29,9 +36,9 @@
         var secondsRound = Math.round(seconds);
         $("#rest_hours").html(hoursRound);
         $("#rest_minutes").html(minutesRound);
-        $("#rest_seconds").html(secondsRound);
+        $("#rest_seconds").html(secondsRound);*/
         //if(total_seconds >0) {
-            setTimeout("getTime("+end_time+");", 1000);
+            //setTimeout("getTime("+end_time+");", 1000);
         //}
     }
 </script>
@@ -41,8 +48,8 @@
       <h1 class="ur_page_title" id="polls_name_h"><%= exercise.exercise_name%></h1>
       <div id="start_time" style="display: none"><%=exercise_user.start_at %></div>
       <div class="fontGrey2">
-        <span class="mr130">开始时间：<%=format_time(exercise_user.start_at.to_s)%></span>
-        <span class="mr130">截止时间：<%=format_time(exercise.end_time.to_s)%></span>
+        <span class="mr100">开始时间：<%=Time.parse(h(exercise_user.start_at)).strftime("%Y-%m-%d %H:%M:%S")%></span>
+        <span class="mr100">截止时间：<%=Time.parse(h(exercise.end_time)).strftime("%Y-%m-%d %H:%M:%S")%></span>
         <% unless exercise.time == -1 %>
             <span class="fr">测验时长：<%=exercise.time %>分钟</span>
         <% end %>
@@ -194,7 +201,7 @@
 
                       }
                   </script>
-                  <input class="fillInput" placeholder="在此填入答案" type="text" value="" onblur="onblur_<%= exercise_question.id %>(this);" <%= @can_edit_excercise?"":"disabled=disabled" %>>
+                  <input class="fillInput" placeholder="在此填入答案" type="text" value="<%= get_anwser_vote_text(exercise_question.id,User.current.id).html_safe %>" onblur="onblur_<%= exercise_question.id %>(this);" <%= @can_edit_excercise?"":"disabled=disabled" %>>
                 </div>
               </div>
             </div>
@@ -202,7 +209,7 @@
       <% end %>
     </div>
     <div class="ur_buttons">
-      <%= link_to l(:button_submit),commit_exercise_exercise_path(exercise), :method => :post,:class => "ur_button_submit",:style => "margin-left:80px;",:format => 'js',:remote=>true %>
+      <%= link_to l(:button_submit),commit_exercise_exercise_path(exercise),:id=>"exercise_submit_btn", :method => :post,:class => "ur_button_submit",:style => "margin-left:80px;",:format => 'js',:remote=>true %>
     </div>
     <div class="cl"></div>
     <!--contentbox end-->
diff --git a/app/views/exercise/_exercise_student_result.html.erb b/app/views/exercise/_exercise_student_result.html.erb
index 8f6ac0e54..3445d6986 100644
--- a/app/views/exercise/_exercise_student_result.html.erb
+++ b/app/views/exercise/_exercise_student_result.html.erb
@@ -10,8 +10,8 @@
     <div class="testStatus"><!--头部显示 start-->
       <h1 class="ur_page_title" id="polls_name_h"><%= exercise.exercise_name%></h1>
       <div class="fontGrey2">
-        <span class="mr130">开始时间：<%=format_time(exercise_user.start_at.to_s) %></span>
-        <span class="mr130">截止时间：<%=format_time(exercise.end_time.to_s)%></span>
+        <span class="mr100">开始时间：<%=Time.parse(h(exercise_user.start_at)).strftime("%Y-%m-%d %H:%M:%S") %></span>
+        <span class="mr100">截止时间：<%=Time.parse(h(exercise.end_time)).strftime("%Y-%m-%d %H:%M:%S")%></span>
         <% unless exercise.time == -1 %>
             <span class="fr">测验时长：<%=exercise.time %>分钟</span>
         <% end %>
@@ -34,7 +34,7 @@
                   <span class="ml15 c_red">
                     <% answer = get_user_answer(exercise_question, User.current)%>
                     <% standard_answer = get_user_standard_answer(exercise_question, User.current)%>
-                    <% if answer.first.exercise_choice.choice_position == standard_answer.first.exercise_choice_id %>
+                    <% if !answer.empty? && !standard_answer.empty? && answer.first.exercise_choice.choice_position == standard_answer.first.exercise_choice_id %>
                         √
                     <% else %>
                         ×
@@ -73,7 +73,7 @@
                   <span class="ml15 c_red">
                     <% answer = get_user_answer(exercise_question, User.current)%>
                     <% standard_answer = get_user_standard_answer(exercise_question, User.current)%>
-                    <% if get_mulscore(exercise_question, User.current).to_i == standard_answer.first.exercise_choice_id %>
+                    <% if !standard_answer.empty? && get_mulscore(exercise_question, User.current).to_i == standard_answer.first.exercise_choice_id %>
                         √
                     <% else %>
                         ×
@@ -112,7 +112,7 @@
                   <span class="ml15 c_red">
                     <% answer = get_user_answer(exercise_question, User.current)%>
                     <% standard_answer = get_user_standard_answer(exercise_question, User.current)%>
-                    <% if standard_answer.include?(answer.first.answer_text) %>
+                    <% if !answer.empty? && !standard_answer.empty? && standard_answer.include?(answer.first.answer_text) %>
                         √
                     <% else %>
                         ×
diff --git a/app/views/exercise/_exercise_teacher.html.erb b/app/views/exercise/_exercise_teacher.html.erb
index 0a96b782b..6e00fc41d 100644
--- a/app/views/exercise/_exercise_teacher.html.erb
+++ b/app/views/exercise/_exercise_teacher.html.erb
@@ -11,9 +11,9 @@
       <h1 class="ur_page_title" id="polls_name_h"><%= exercise.exercise_name%></h1>
       <div class="fontGrey2">
         <% unless exercise.publish_time.nil? %>
-            <span class="mr130">发布时间：<%=format_time(exercise.publish_time.to_s) %></span>
+            <span class="mr100">发布时间：<%=Time.parse(h(exercise.publish_time)).strftime("%Y-%m-%d %H:%M:%S") %></span>
         <% end %>
-        <span class="mr130">截止时间：<%=format_time(exercise.end_time.to_s) %></span>
+        <span class="mr100">截止时间：<%=Time.parse(h(exercise.end_time)).strftime("%Y-%m-%d %H:%M:%S") %></span>
         <% if exercise.time != -1 %>
             <span class="fr">测验时长：<%=exercise.time %>分钟</span>
         <% end %>
diff --git a/app/views/exercise/_show_head.html.erb b/app/views/exercise/_show_head.html.erb
index 16a572583..f385e58b8 100644
--- a/app/views/exercise/_show_head.html.erb
+++ b/app/views/exercise/_show_head.html.erb
@@ -4,9 +4,9 @@
   <h1 class="ur_page_title" id="polls_name_h"><%= exercise.exercise_name%></h1>
   <div class="fontGrey2">
     <% unless exercise.publish_time.nil? %>
-        <span class="mr100">发布时间：<%=Time.parse(format_time(exercise.publish_time)).strftime("%Y-%m-%d %H:%M:%S") if exercise.publish_time%></span>
+        <span class="mr100">发布时间：<%=Time.parse(h(exercise.publish_time)).strftime("%Y-%m-%d %H:%M:%S") if exercise.publish_time%></span>
     <% end %>
-    <span class="mr100">截止时间：<%=Time.parse(format_time(exercise.end_time)).strftime("%Y-%m-%d %H:%M:%S") if exercise.end_time %></span>
+    <span class="mr100">截止时间：<%=Time.parse(h(exercise.end_time)).strftime("%Y-%m-%d %H:%M:%S") if exercise.end_time %></span>
     <% if exercise.time != -1 %>
         <span>测验时长：<%= exercise.time %>分钟</span>
     <% end %>
diff --git a/app/views/exercise/commit_exercise.js.erb b/app/views/exercise/commit_exercise.js.erb
index 2a40df2a5..5ede8a951 100644
--- a/app/views/exercise/commit_exercise.js.erb
+++ b/app/views/exercise/commit_exercise.js.erb
@@ -1,4 +1,4 @@
-$('#ajax-modal').html('<%= escape_javascript(render :partial => 'commit_alert',:locals => {:status => @status}) %>');
+$('#ajax-modal').html('<%= escape_javascript(render :partial => 'commit_alert',:locals => {:status => @status,:exercise =>@exercise}) %>');
 showModal('ajax-modal', '270px');
 $('#ajax-modal').css('height','110px');
 $('#ajax-modal').siblings().remove();
diff --git a/public/stylesheets/courses.css b/public/stylesheets/courses.css
index b7a742994..17ed37e05 100644
--- a/public/stylesheets/courses.css
+++ b/public/stylesheets/courses.css
@@ -1166,4 +1166,5 @@ a:hover.testEdit{ background:url(images/icons.png) -21px -272px  no-repeat;}
 .questionEditContainer {border:1px solid #cbcbcb;background:#eeeeee; padding:10px; margin-bottom:10px; margin-top:10px;}
 .fillInput {border:1px solid #cbcbcb; padding-left:5px; background-color:#ffffff; width:693px; height:30px; color:#888888;}
 .mr130 {margin-right:130px;}
+.mr100 {margin-right:100px;}
 .ur_button_submit{ display:block; width:106px; height:31px; margin:0 auto; background:#15bccf; color:#fff; font-size:16px; text-align:center; padding-top:4px; margin-bottom:10px; }
\ No newline at end of file