help: Constaints Based on Data of Other Tables

Hi,
Do anybody know if I can use actual data of existing table for using in constraint on a column in another table?

I have a table JOBS:

JCODE CHAR(2) NOT NULL
MIN_PAY NUMBER NOT NULL
MAX_PAY NUMBER NOT NULL
Unique(JCODE)

And I want to create a table ASSIGNMENT:

EID NUMBER NOT NULL
JCODE REFERENCES JOBS(JCODE)
SALARY ------!!------ - is is my question below

I am trying define column SALARY so that it could contain only values in the range set in the tabke JOBS for same JCODE and this is what I write:

SALARY NUMBER CHECK (
  SALARY >= (select MIN_PAY from JOBS

               where JOBS.JCODE = JCODE) AND SALARY <= (select MAX_PAY from JOBS

                 where JOBS.JCODE = JCODE) 

Oracle complains on JOBS.JCODE: only simple column names allowed here

Is there another solution involving constraints?

Thank you very much.

--
David Zlotchenko
Research Services
The University of Tennessee            Phone: (615) 974-2909
211 Hoskins Library                    Email: zlotchen_at_solar.rtd.utk.edu
Knoxville, TN  37996                          s_dzlotchenk_at_pstcc.cc.tn.us