01 * * * * root /var/sun/./chk.sh > /dev/null 2>&1
I can see many things
1. This script will execute 1st minute of every hour. So You have to wait for an hour to get some output from it.
chk.sh, Is the part in Color Red Intentional. Although it will work.
3. Rather than directing the STDOUT and STDERR to /dev/null redirect them to a file. This might help in finding possible errors.