Catch Command R in Safari with JQuery

Question

I need to intercept the browser-reload-functionality in Safari (I know this is usually not something one should do, but in my case this makes sense).

For Windows I just do this:

$(document).keydown(function(event) {
    if ( event.which == 116 ) {
        restart();
        return false;
    }
});

Do I need to use a JQuery Plugin to capture two Keys at the same time or is this already implemented in JQuery in some form?

Also, are the keycodes under Mac the same as they are under windows? ("Command" being the keycode "17" and "r" being "19"?) or is it "55" for the command key and "15" for "r"?