function disable (value) {
  if (value == 'return') {
    document.getElementById('whichway').disabled = true;
    document.getElementById('transfer-type-write').style.color = '#EFEFEF';
    document.getElementById('whichway').style.backgroundColor = '#EFEFEF';
    document.getElementById('from').style.color = '#999999';
  }
  else if (value == 'oneway') {
    document.getElementById('whichway').disabled = false;
    document.getElementById('from').style.color = '#333333';
    document.getElementById('whichway').style.backgroundColor = '#FFFFFF';
  }
}