Move up and down listbox item using javascript ~ Ronaldo CR7

In the following example,we can easy to move the list box item up and down using javascript code.
Example


    function listboxMove(listID, direction) {

      var listbox = document.getElementById(listID);

      var selIndex = listbox.selectedIndex;

      if (-1 == selIndex) {

        alert("Please select an option to move.");

        return;

      }

      var increment = -1;

      if (direction == 'up')

        increment = -1;

      else

        increment = 1;

      if ((selIndex + increment) < 0 ||

        (selIndex + increment) > (listbox.options.length - 1)) {

        return;

      }

      var selValue = listbox.options[selIndex].value;

      var selText = listbox.options[selIndex].text;

      listbox.options[selIndex].value = listbox.options[selIndex + increment].value

      listbox.options[selIndex].text = listbox.options[selIndex + increment].text

      listbox.options[selIndex + increment].value = selValue;

      listbox.options[selIndex + increment].text = selText;

      listbox.selectedIndex = selIndex + increment;

    }