创建触发器在on处语法错误

CREATE TRIGGER tri_xke ON xke
FOR INSERT,UPDATE
AS
IF(SELECT COUNT(*) FROM xsheng,inserted
WHERE xke.kchhao=inserted.kchhao)>70
BEGIN
PRINT '该课程选课人数不能超过70个！'
ROLLBACK
END

显示语法错误在“ON”或附近的