Need help setting up: Apache Reverse Proxy

I have some trouble setting my virtualhosts file up the right way. I'd like to send vistors to the right server by using reverse proxy. My current setup gives me an internal error.

i have only 1 public ip and want to proxy the visitor on the condition of the right servername to one of the local virtual servers.

NameVirtualHost *:80

<VirtualHost *:80>
    ServerName sub.domain.com
    ServerAdmin me@domain.com
    ProxyPreserveHost On
    ProxyPass / http://192.168.1.11:80
    ProxyPassReverse / http://192.168.1.11:80
</VirtualHost>

<VirtualHost *:80>
    ServerName otherdomain.com
    ServerAdmin me@domain.com
    ProxyPreserveHost On
    ProxyPass / http://192.168.1.12:80
    ProxyPassReverse / http://192.168.1.12:80
</VirtualHost>

If someone can find anything I'm doing wrong or has another way to achieve my goal i'd love to hear so..

Solution

Got it working! used the following setup:

<VirtualHost *:80>
    ServerName sub.domain.com
    ServerAdmin me@domain.com

    ProxyRequests Off

    ProxyPreserveHost On

    <Proxy *>
        Order deny,allow
        Allow from all
    </Proxy>

    ProxyPass / http://192.168.1.11/websvn/
    ProxyPassReverse / http://192.168.1.11/websvn/
</VirtualHost>

the /websvn/ part was neccesary to include the css and other files properly

In another loaded .conf file:

 LoadModule proxy_connect_module /usr/lib/apache2/modules/mod_proxy_connect.so
 LoadModule proxy_ftp_module /usr/lib/apache2/modules/mod_proxy_ftp.so
 LoadModule proxy_http_module /usr/lib/apache2/modules/mod_proxy_http.so

Which is used to inlcude the neccesary modules