This works:
<select name="foo" id="foo">
<option value="1">a</option>
<option value="2">b</option>
<option value="3">c</option>
</select>
<input type="button" id="button" value="Button" />
$('#button').click(function() {
alert($('#foo option:selected').text());
alert($('#foo option:selected').val());
});