I'm using the module Privatemsg to give users the possibility to send messages to other users on the website.
What I would like to do is:
A button on the detail page of node with type equal to Proposal, and when a user clicks on it a, they redirect to the page
messages/new where the subject and message is already filled in.
Now I just have a static button on the detail page that doesn't do anything. But how can I create the functionality that they redirect and 2 form parameters are already filled in?