Mount NFS after boot

[Linda]

Anyone have a suggestion how to automatically mount an NFS 
share after boot? I had it set for auto in fstab, but than 
if the share is not available it hangs. After having to boot 
from a cd and edit fstab to get a computer to boot I want to 
avoid that solution. I have a script users can use to mount 
the NFS share if I have forgot to remount them after the 
system is rebooted, however they often call in a panic 
because their files are gone.  I could stick the script call 
in their bash files but then it would try to mount them even 
when they are already mounted.
                        Thanks
                         Linda