I have a problem with full disk

-rw-rw----  1 mysql mysql 1073741982 2012-07-03 18:14 mysql-bin.000034
-rw-rw----  1 mysql mysql 1073741890 2012-07-04 14:39 mysql-bin.000035
-rw-rw----  1 mysql mysql 1073741988 2012-07-05 09:16 mysql-bin.000036
-rw-rw----  1 mysql mysql 1073741964 2012-07-06 00:04 mysql-bin.000037
-rw-rw----  1 mysql mysql 1073741974 2012-07-06 21:45 mysql-bin.000038
-rw-rw----  1 mysql mysql 1073741923 2012-07-07 19:05 mysql-bin.000039
-rw-rw----  1 mysql mysql  356167680 2012-07-07 23:47 mysql-bin.000040

my.cnf:

max_binlog_size = 1073741824
log-bin = mysql-bin
max_relay_log_size = 1G
relay_log_space_limit = 2G

mysql is creating files mysql-bin.xxxxx and my disk is full after several days.

How to make mysql to delete old logs ?