borus,
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<script src="http://code.jquery.com/jquery-latest.js"></script>
<script>
$(function(){
var sel = $('#baget_select'),
foo = function(){alert($(':selected',sel).text())};
foo();
$('body').on('change', sel, foo)
});
</script>
</head>
<body>
<select id="baget_select" name="" size="1" >
<option value="12345">светлый</option>
<option value="5723">темный</option>
</select>
</body>
</html>