jQuery的重点在于你不必担心浏览器差异。我很确定你可以安全地使用输入在所有浏览器中都是13。所以考虑到这一点，你可以这样做：

The whole point of jQuery is that you don't have to worry about browser differences. I am pretty sure you can safely go with enter being 13 in all browsers. So with that in mind, you can do this:

$(document).on('keypress',function(e) {
    if(e.which == 13) {
        alert('You pressed enter!');
    }
});