Thanks for the welcome and the reply I appreciate it (and sorry for the bulk of information, I figured better to much then to little).
My controller impression came from this tutorial
and makes sense to me, however this would not be the place to discuss this.
, where a similar solution is done). And basically that is the same I do with the 'open' note link which does a postback and fires the "editDoc" method in the EindOpdrachtContr class.
So what I basically want is for the selectOneMenu to make a roundtrip to the server when the users changes its value and the response should contain the updated Note textarea.