Shell Programming and Scripting

Hi,

I have a problem for ftp file to server. If the server due to some reason (such as unstable) and disconnect my ftp script. Can the ftp keep automatic retry to connect? If yes, the files can be keep sending to host without duplicate?

HOST=hostname
USER=happyv
PASSWD=happyv

exec 4>&1
ftp -nv >&4 2>&4 |&

print -p open $HOST
print -p user $USER $PASSWD
print -p cd csl
print -p binary
print -p put CDN00173.gz
print -p put CDN00174.gz
print -p put CDN0175.gz

wait
exit 0


150 Ready to receive "/CDN00174". Mode STREAM Type BINARY.
netout: Broken pipe
421 Server is going offline. Control connection closed.
Not connected.
Not connected.
Not connected.
Not connected.
Not connected.
Not connected.
Not connected.

yes, something like : "if then else", or "while loop" with implementing retry

Thanks..but can you give me some idea or code for this?