Insert error

Question

I am getting an error in the FORMN in the following:

INSERT

INTO PROFADJUST(ClaimNbr, ClaimLine, Copay, Deduct, SubmissionPeriod)

SELECT cast((FORMN + 'E' + CHKDT) AS varchar2(17)),

CLMSQ

,COPAM,DCTAM,CHKDTFROM HENCDP;

Any idea?
arep