Copy and paste the following line into a text file. See also this faq for information on how to use the configuration file.

www.blrf.net

# This is configuration file for
# http://www.blrf.net/dyndns/
# dynamic DNS service provider.
#
# You need to put your password and hash
# on this configuration file
# (look at the user_pass and user_hash below).
# You can get that by visiting
# http://www.blrf.net/dyndns/edit.php
#
# Enter hostname on program without domain name

[default]
withpass=0
host=dyndns.blrf.net
port=80
path=/update.php

[requests]
user_domain=%HOST%
user_pass=[place your password here]
user_hash=[place your hash here]
ip_address=%IP%

[result]
success=ERROR:0:STR_ERROR:
warning=ERROR:1001:STR_ERROR:
multilines=1