cruise control

how do i use cruise control in a C 250 TDI of 1996 ?
i see some + and - on the dashboard does that have something to do with it ?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.