how to change select option by jquery code example

Example 1: dropdown option selection change event in jquery

$("select [name='element_name']").change(function(){
	// condition goes here
});

Example 2: click select option to update div jquery

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