HELP: Can't pass value to hidden fields

HELP: Can't pass value to hidden fields

Hi!,

jQuery newbie here. As you can see the codes bellow, I'm trying to pass a value after such event, basically returning the date and age to hidden fields.

// Compute age (fld_age) according DOB fields
  $('#fld_birth_yy, #fld_birth_mm, #fld_birth_dd').on('change', function(e){
    e.preventDefault();
    if ($('#fld_birth_yy').val() != 0 && $('#fld_birth_mm').val() != 0 && $('#fld_birth_dd').val() != 0) {
      var str_dob = $('#fld_birth_yy').val() + '/' + $('#fld_birth_mm').val() + '/' + $('#fld_birth_dd').val();
      $('input[name="fld_dob"]').val(str_dob); 
      $('input[name="fld_age"]').val(calcAge(str_dob));   
      console.log(calcAge(str_dob));
    }
  });

  function calcAge(dateString) {
    var birthday = +new Date(dateString);
    return~~ ((Date.now() - birthday) / (31557600000));
  }

Please point-out what I'm missing...

Thanks Much!

vrsotto