课程发布通知的在ie11下的bug

public/javascripts/course.js

@@ -282,7 +282,7 @@ function regexTitle()
 function regexDescription()
 {
     var name = news_description_editor.html();
-    if(name.length ==0)
+    if(news_description_editor.isEmpty())
     {
         $("#description_notice_span").text("描述不能为空");
         $("#description_notice_span").css('color','#ff0000');