Handling keyboard shortcuts for webapp
In JS, when you have a switch, it's usually better to go with a dispatch table.

var mapping = {
    82: newDoc,
    79: openDoc,
    83: saveDoc,
    66: function() {
        showHideStatusBar(statusBarOn ? false : true);
    },
    191: function() {
        alert("Welcome to " + appname + "!");
    }
};
mapping[e.keyCode]();


Or if you don't want to give a name:

({
    82: newDoc,
    79: openDoc,
    83: saveDoc,
    66: function() {
        showHideStatusBar(statusBarOn ? false : true);
    },
    191: function() {
        alert("Welcome to " + appname + "!");
    }
})[e.keyCode]();


Also, use === instead of == for multiple reasons. Google "triple equal javascript" if you want more information.