Apache Virtual Host ServerName

Hi,

I was trying to set up a (test) virtual host with Apache2 on Ubuntu but I get this error :

AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message

I do not understand since I already created this :

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    ServerName your_domain
    ServerAlias www.your_domain
    DocumentRoot /var/www/your_domain
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

Thanks for answering and sorry for (eventual) bad English!