Simple Oracle incremental backup in Bash script

Here's my script. I call it ora_backup.sh. I put it in Oracle home folder and gave permission to Oracle user to execute it. Run the following script as Oracle user. Usually I run the incremental level 0 in the weekend and run level 1 for the rest. Just add 0 or 1 at the end of command (e.g.: ./ora_backup.sh 0).

http://pastebin.com/raw.php?i=hnmfjgxh