A screenshot should help. First notice on the left side there is a variable named ClosedOrOpen. Then in the top right corner notice it is set to RepNotify. Setting that automatically creates a function called OnRep_ClosedOrOpen. You can see that function in the center. This is the code that runs on each networked client when the value of ClosedOrOpen changes on the server. This function is responsible for moving the door to the open or closed position in the world.
