I have 2 tables

JOBS

JOBNO HRSWORKED
111 12
111 1
111 3

222 4
222 6

JOBLT

JOBNO BUDGETEDHRS
111 20
222 10

SELECT JOBNO, BUDGETEDHRS, (SELECT SUM (HRSWORKED) FROM JOBS WHERE JOBS.JOBNO= JOBLT.JOBNO GROUP BY JOBS.JOBNO ) AS TOTALHRSWORKED , (TOTALHRSWORKED-BUDGETEDHRS) AS OVERBUDGET
FROM JOBLT ORDER BY JOBNO

Here I am getting the error TOTALHRSWORKED as invalid column

How can I fix that?
thx