<VirtualHost *:80>
DocumentRoot "/var/www/sites/site1"
ServerName "site1.ru"
Alias /styles /var/www/sites/styles
Alias /js /var/www/sites/js
</VirtualHost>
<VirtualHost *:80>
DocumentRoot "/var/www/sites/site2"
ServerName "site2.ru"
Alias /styles /var/www/sites/styles
Alias /js /var/www/sites/js
</VirtualHost>