cron job (SCO) and INFORMIX

I need to run a shell script that calls dbaccess, sacego and ISQL. I've set it up so that it sets all the environment variables and the path, yet I still get an error from cron that the executables can't be found. My script is of the form SET INFORMIXSERVER mecho_s; export INFORMIXSERVER etc. etc. dbaccess pic xxx ISQL xxx Can anyone help? Thanks, Kate