diff --git a/db/StoredProcedures.sql b/db/StoredProcedures.sql
index bc50e1d762f39733035ab98d416487d0f7f9f081..ef6ac33e4af02f12a9487c25fc616c19a025a259 100644
--- a/db/StoredProcedures.sql
+++ b/db/StoredProcedures.sql
@@ -1038,6 +1038,10 @@ BEGIN
     DECLARE semID, checker INT; 
     SET semID = GetCurSemesterID();   
 
+	IF NOT (Grade > 0) THEN
+		RETURN -1;
+	END IF; 
+
     SELECT departments.ID
     INTO checker
     FROM `departments`
@@ -1058,6 +1062,7 @@ BEGIN
 	END IF;
 
 
+
 	INSERT INTO `disciplines` 	(	disciplines.AuthorID, 
 									disciplines.Grade, 
 									disciplines.SubjectID,