Message function for CakePHP Website

Hello Freelancers! I have already a CakePHP Homepage but there is a problem with the message function. There are 2 types of Usergroups, Teachers and Students. It is a German Homepage. I will describe the Problem now: #The Usergroup Students needs to write Messages to the Teachers. here is a link of the Page i want to do that. This is a link of a Teacher profile: [login to view URL]:45/slug:Manuel You can see there a Button called "Nachricht senden" this means "send message". But at the moment it hasn't a function, But i want to change that. I'm wating for Bids Greetings from Germany