I try to replace certain record in my table, when i issue the replace statement as below :

REPLACE CURRCODE WITH SYS(2015) FOR CURRCODE=thisform.pageframe1.page1.txtCode

The error below came out :

OPERATION IS INVALID FOR A MEMO, GENERAL OR PICTURE FIELD.

But when I replace thisform.pageframe1.page1.txtCode with the constant example "333", and it works.

Can anyone tell me Why?

Thank U very much.