SQL Server 2008 R2 - triggers

CREATE DATABASE EMPLOYEES
USE EMPLOYEES

CREATE TABLE SAL_INFO(GRADE CHAR(2),SAL NUMERIC(8,2))
SELECT * FROM SAL_INFO

INSERT INTO SAL_INFO VALUES('A',50000)
INSERT INTO SAL_INFO VALUES('B',40000)
INSERT INTO SAL_INFO VALUES('C',30000)
SELECT * FROM SAL_INFO

CREATE TABLE EMP(EMP_NO INT,EMP_NAME VARCHAR(50),DEPT_NO CHAR(5),GRADE CHAR(2),BSAL NUMERIC(8,2))
SELECT * FROM EMP

CREATE TRIGGER TR_EMP ON EMP
FOR INSERT,UPDATE
AS
DECLARE @SAL NUMERIC(8,2)
SELECT @SAL = SAL_INFO.SAL FROM SAL_INFO,INSERTED
WHERE INSERTED.GRADE = SAL_INFO.GRADE
UPDATE EMP SET BSAL = @SAL FROM EMP,INSERTED
WHERE EMP.EMP_NO =  INSERTED.EMP_NO

INSERT INTO EMP VALUES(1001,'SAJU','D101','A',NULL)
INSERT INTO EMP VALUES(1002,'MUJI','D102','B',NULL)
INSERT INTO EMP VALUES(1003,'NIYAS','D103','C',NULL)
SELECT * FROM EMP