Allow right clicking on pics on an image host

NOTE: project may involve viewing adult images I have a free image host called [login to view URL] and It has an admin. The job involves adding an option on the admin where the webmaster can ENABLE or DISABLE right click on pictures when visitors open a picture page. Currently, the site allows right click ONLY when you click on a VIEW IMAGE IN ACTUAL SIZE button, but I need to allow direct right click from picture page as well, without having to click on VIEW IMAGE IN ACTUAL SIZE button. That's all. Site uses PHP and ZEND The option would appear in the admin, as a check box, on Settings page. I'll provide access to admin