I have the following Javascript:
$(function(){
    $("#foo").keypress(function (event) {
        if (event.keyCode == 13) {
            console.log(event.ctrlKey ? "Ctrl+Enter (13)" : "Enter (13)");   
        }
        else if (event.keyCode == 10) {
            console.log(event.ctrlKey ? "Ctrl+Enter (10)" : "Enter (10)");
        }
    });
});
Foo in this case is an input box.
Under Windows, and Windows only - holding down the CTRL modifier changes the keyCode from 13 to 10. So if I do Enter v.s. CTRL + Enter, I see Enter (13) and Ctrl+Enter (10) in the console. Mac OS and Linux don't do this regardless of browser.
Why is this?
Fiddle to play with at http://jsfiddle.net/K6NhF/