automatically umount a samba share?

[Christopher J. Bottaro]

is there anyway to automatically unmount a samba share when the connection
is lost?  i frequently shutdown my windows machine before i remember to
unmount the samba shares on my linux box.  then on my linux box, whenever i
try to do anything with the mount point, it just freezes...not even
smbumount will work on it.

thanks for the help.