移动option

(function() {
  var leftSelectObj = document.getElementById('leftSelect');
  var leftBtnUp = document.getElementById('left_btn_up');
  var leftBtnDown = document.getElementById('left_btn_down');
  var rightSelectObj = document.getElementById('rightSelect');
  var rightBtnUp = document.getElementById('right_btn_up');
  var rightBtnDown = document.getElementById('right_btn_down');
  var btnLeft = document.getElementById('btn_left');
  var btnLeftAll = document.getElementById('btn_left_all');
  var btnRight = document.getElementById('btn_right');
  var btnRightAll = document.getElementById('btn_right_all');

  leftBtnDown.onclick = function() {
    var index = leftSelectObj.selectedIndex;
    if(index !== -1) {
      if(index === leftSelectObj.length - 1) {
        leftSelectObj.insertBefore(leftSelectObj.children[index], leftSelectObj.children[0]);
      } else {
        leftSelectObj.insertBefore(leftSelectObj.children[index], leftSelectObj.children[index + 2]);
      }
    }
  };

  leftBtnUp.onclick = function() {
    var index = leftSelectObj.selectedIndex;
    if(index !== -1) {
      if(index === 0) {
        leftSelectObj.appendChild(leftSelectObj.children[index]);
      } else {
        leftSelectObj.insertBefore(leftSelectObj.children[index], leftSelectObj.children[index - 1]);
      }
    }
  };

  btnRight.onclick = function() {
    var index = leftSelectObj.selectedIndex;
    if(index !== -1) {
      rightSelectObj.appendChild(leftSelectObj.children[index]);
    }
  };

  btnRightAll.onclick = function() {
    for(var i = 0; i < leftSelectObj.length; ++i) {
      rightSelectObj.appendChild(leftSelectObj.children[i]);
      --i;
    }
  };
})();