Navigator Button on/off shall always be kept

Customer is requesting to have a very easy option to show/not show the navigator. Without saving this and overruling all other options to show/not show the Navigator. No separate saving shall be neccessary, just one click to show/not show and keep this for ever. This problem is always coming up, when Radiologists are having conferences, there is a very easy option neccessary to show/not show the navigator - auto hide option is not enough due to customer.