jQuery(function($){
    $('form input').change(function() { // works when input will be blured and the value was changed
        //alert('input value changed');
        $('.log').append(' change');
    });
    $('form input').keyup(function() { // works immediately when user press button inside of the input
        $(this).change(); // simulate "change" event
    });
});

<form>
    <input type="text" placeholder="type here to test events...">
    <div class="log">log of change and keyup events. </div>
</form>