[SOLVED] Unselect multiple items via JS

How Do I...
#1

Hi!
I’ve a select (multiple) and there is some item with different label but same id.

<option value="20">John Moore</option>
<option value="6">Mike Bloom</option>
<option value="20">Dr. J. Moore</option>

I would like to unselect all ID 3 items when user unselect one of them (click on X).
This is my code

  /* delete multiple users from select */
  $('select[multiple]').on("select2:unselect", function (e) {
    // get deleted ID
    var user_id = e.params.data.id; 
    // select obj
    var select = $(this); 
    // get all items
    select.find(':selected').each(function(key, el) { 
      // check if ID is the same
      if (el.value == user_id) {
        // here the code to unselect current el
      }
    });
  });

how can I unselect an element?
Or there is a way to prevent select items with same value?

#2

solved

  $('select[multiple]').on("select2:unselect", function (e) {
    e.preventDefault();
    var user_id = e.params.data.id;
    var select = $(this);
    select.find(':selected').each(function(key, el) {
      if (el.value == user_id) {
        $(el).attr('selected', false);
      }
      select.trigger('change');
    });
  });