javascript on change method and then change value code example

Example 1: click select option to update div jquery

$('#choose').change(function(event) {
        $.post('info.php', { selected: $('#choose').val() },
            function(data) {
                $('#update').html(data);
            }
        );            
    });

Example 2: jquery detect textarea change

$('#myTextAreaID').on('input propertychange paste', function() {
    //my Textarea content has changed
});