code: function (val) {
              var unique;
              if (this.select) {
                  this.select.val(val);
              } else {
                  unique = [];
                  // filter out duplicates
                  $(val).each(function () {
                      if (indexOf(this, unique) < 0) unique.push(this);
                  });
                  this.opts.element.val(unique.length === 0 ? "" : unique.join(this.opts.separator));
              }
          }
docs: multi