SSL and client cert

Hi All
I'm trying to send a client cert in my soap request. In my web service I have the following code:

X509Certificate[] certificateChain = (X509Certificate[])httpServletRequest.getAttribute("javax.servlet.request.X509Certificate");

certificateChain is always null.

I have created a client cert (followed instructions here http://stackoverflow.com/questions/1180 ... ertificate), added it to a keystore and have specified the keystore in the Project preferences/SSL Settings, and in WS-Security Configurations (Keystores /Certificates). I've also specified the keystore in the Request properties (SSL Keystore), but when viewing the Raw request information, the certificate is not being sent in the Request.

What am I doing wrong? Does this work with the trial version of SoapUI or do I need a license for this feature?

Thanks in advance.