You need to create a virtual host.
<VirtualHost demo.wmanager.org:80>
ServerAdmin webmaster@partnertecnologico.it
DocumentRoot /var/www/tests/demo.wmanager.org/
ServerName demo.wmanager.org
ServerAlias demo.wmanager.org
ErrorLog /var/log/httpd/demo.wmanager.org-error_log
CustomLog /var/log/httpd/demo.wmanager.org-access_log common
#SetEnv FLOW_CONTEXT Production
<Location />
Options FollowSymLinks
# AddDefaultCharset ISO-8859-1
</Location>
</VirtualHost>
<Directory "/var/www/tests/demo.wmanager.org/">
#Options -Indexes +MultiViews +FollowSymLinks
#AllowOverride Options AuthConfig Indexes FileInfo
AllowOverride AuthConfig FileInfo Indexes Limit Options=All,MultiViews
Order allow,deny
Allow from all
</Directory>