suporte a onEnter e onShiftEnter para inputs

onEnter.js

$.fn.onEnter = function(callback, selector, data, onlyIfShiftKeyPressed){
    if($.isFunction(callback)) {
        $(this).on('keydown.onEnter', selector, data, function(e) {
            if(e.which != 13) return true;
            if(onlyIfShiftKeyPressed && !e.shiftKey) return true;
            e.preventDefault();
            callback.apply(this, [e]);
        });
    }

    return this;
};

$.fn.onShiftEnter = function(callback, selector, data){
    $(this).onEnter(callback, selector, data, true);
    return this;
};

demo em http://jsfiddle.net/rodolfo42/5LyMj/