jquery change select value

1$('select').on('change', function() {
2  alert( this.value );
3});

1$('select option[value=8272]').attr('selected', '');

1$('#ddlID').val('New_OptionValue').change()

1$("#mySelectElementID").val("my_new_value"); //change selected option/value with jQuery
2

1    $('#choose').change(function(event) {
2        $.post('info.php', { selected: $('#choose').val() },
3            function(data) {
4                $('#update').html(data);
5            }
6        );            
7    });

1$("div.id_100 select").val("val2");
2