Forum Moderators: open
Right click is already disabled
And that won't work on any non-IE browser or if the person has Javascript disabled - and even if it did, you can get the URL from the page properties option in the top menu. There is simply no way of hiding the URL of a page - if the person can access the page, it is because their system knows the URL, and so can display it.
If you want bonus items to be available to certain users, then you should look at using a cookie or session ID to target qualifying customers - then even if someone has the URL, it won't work unless they have gone through the right process.