课程内发布作业失败

public/javascripts/course.js

@@ -666,6 +666,7 @@ function regex_homework_end_publish_time()
         $("#homework_publish_time").val(myDate.toLocaleDateString());
     }
     var publish_time = Date.parse($("#homework_publish_time").val());
+    var end_time = Date.parse($("#homework_end_time").val());
     if(end_time < publish_time)
     {
         $("#homework_end_time_span").text("截止日期不能小于发布日期");