Hi This is what I do
hope it helps

#
# launch ftp program and write to FTP_LOG FILE
#
FTP_LOG= ${USR_HOME}"FTP_LOG".lis

$FTP_PROG $USR@$IPN -pw=$PSS -ce -unat=y -cmd="$CMDS;" >>${FTP_LOG}
RTNCD=$?
#
#check the return code for error
# look for error message in the log and email admin
#
if [[ !0 = $RTNCD ]]
then
echo "FTP ERROR: "$RTNCD >>$O_ERR
awk -F '[:.]' '$1 == "Warning" { print $2 }' ${USR_HOME}${FTP_LOG}
>>$O_ERR
awk -F '[:.]' '$1 == "Error" { print $2 }' ${USR_HOME}${FTP_LOG}
>>$O_ERR
send_mail
fi