<script type="text/javascript">

function _set(){

// birth[0]→year, birth[1]→month, birth[2]→day

var _birth = parseInt("" + $('#year').val() + affixZero($('#month').val()) + affixZero($('#day').val()) );

var  today = new Date();

var _today = parseInt("" + today.getFullYear() + affixZero(today.getMonth() + 1) + affixZero(today.getDate()));

$('#age').val(parseInt((_today - _birth) / 10000));

}

function affixZero(int) {

if (int < 10) int = "0" + int;

return "" + int;

}

</script>