I've got the answer :)

Following script worked...

#!/bin/ksh
REM_USER="Username"
REM_PASS="PASSWORD"
REM_HOST="host.name"
echo "Please Enter the File Name"
read FILE_NAME

ftp -nv <<EOF
open $REM_HOST
user $REM_USER $REM_PASS
cd /abc/My_Dir
mput $FILE_NAME
EOF