Man who try squeeze water out of stone too hard end up getting water out of hand.
I have no idea how this relates to anything, but if anyone asks this question again I'm going to go supernova in a giant ball of pure nova-hot rage and obliterate the universe. Some people would call that harsh, but I don't honestly think it deserves to exist if humanity is all it can come up with.
sgrkadam the simple reason why you can not find an answer to your question is because there isn't one. Disabling funamental functions of browsers is a security concern above all else, and a bloody nuisance for any user who wants to use those functions for legitimate purposes.
Any casual save is hardly going to do you any harm, and anyone determined to save your content will do so no matter what you try. You might as well try and protect the air you're breathing by frantically waving your hands in circles and gathering up the air molecules.
If you're that determined, you could also have your site spawn a new window for your content with all the menus removed. Then you can laugh maniacally as the determined save-as monster tries to find the menu!