Yup, like I expected.
This isn't panning, this is simple sidescrolling =)
You can create this by having a statement which checks the mouse position on screen, and if it is less then 5, move the camera to the left, or if it is more then screenwidth -5, move the camera to the right. Don't forget to include a statement to check if the camera hasn't moved to the right already, otherwise it will continue to go to a side meaning you have to wait a long time before you can move to the other side.