diff --git a/public/javascripts/course.js b/public/javascripts/course.js
index 7a93ab3ef..90d085ea3 100644
--- a/public/javascripts/course.js
+++ b/public/javascripts/course.js
@@ -176,7 +176,7 @@ function regexTopicSubject() {
 function regexTopicDescription()
 {
     var name = message_content_editor.html();
-    if(name.length ==0)
+    if(message_content_editor.isEmpty())
     {
         $("#message_content_span").text("描述不能为空");
         $("#message_content_span").css('color','#ff0000');
@@ -327,7 +327,7 @@ function submitComment()
 
 function newsReplyVerify() {
     var content = comment_editor.html();
-    if(content.length == 0) {
+    if(comment_editor.isEmpty()) {
         $("#add_reply_news").text("评论不能为空");
         $("#add_reply_news").css('color', '#ff0000');
         return false;
@@ -356,7 +356,7 @@ function course_board_canel_message_replay()
 
 function MessageReplayVevify() {
     var content = message_content_editor.html();//$.trim($("#message_content").val());
-    if (content.length == 0) {
+    if (message_content_editor.isEmpty()) {
         $("#message_content_span").text("回复不能为空");
         $("#message_content_span").css('color', '#ff0000');
         return  false;