Asterisk message

Hello everybody
I have asterisk 1.4 installed
i get a lot of this messages
what and why is that?
is that necesary?
can i block that?
thanks a lot

== Manager ‘admin’ logged off from 127.0.0.1
== Parsing ‘/etc/asterisk/manager.conf’: Found
== Manager ‘admin’ logged on from 127.0.0.1
== Manager ‘admin’ logged off from 127.0.0.1
== Parsing ‘/etc/asterisk/manager.conf’: Found
== Manager ‘admin’ logged on from 127.0.0.1
== Manager ‘admin’ logged off from 127.0.0.1
== Parsing ‘/etc/asterisk/manager.conf’: Found
== Manager ‘admin’ logged on from 127.0.0.1
== Manager ‘admin’ logged off from 127.0.0.1
== Parsing ‘/etc/asterisk/manager.conf’: Found
== Manager ‘admin’ logged on from 127.0.0.1
== Parsing ‘/etc/asterisk/manager.conf’: Found
== Manager ‘admin’ logged on from 127.0.0.1
== Manager ‘admin’ logged off from 127.0.0.1
== Manager ‘admin’ logged off from 127.0.0.1
== Parsing ‘/etc/asterisk/manager.conf’: Found
== Manager ‘admin’ logged on from 127.0.0.1
== Manager ‘admin’ logged off from 127.0.0.1
== Parsing ‘/etc/asterisk/manager.conf’: Found
== Manager ‘admin’ logged on from 127.0.0.1
== Manager ‘admin’ logged off from 127.0.0.1
== Parsing ‘/etc/asterisk/manager.conf’: Found
== Manager ‘admin’ logged on from 127.0.0.1