(function ( $ ) {
      $.fn.mutarSelect = function( options ){
  
  
          // This is the easiest way to have default options.
          var settings = $.extend({
          valueselector:"Agregar nuevo",
          }, options );
  
          var selector = this;
          selector.append("<option value='' class='mutarselect-add'>" + settings.valueselector + "</option>");
      
          $(".mutarselect-add").click(function( event ){
                  event.preventDefault();
                  
                  //alert($(this).parent(".mutarselect").attr("id"));
                  var father = $(this).parent(selector).attr("id");
                  //var positionReal = $(this).parent(".mutarselect").offset();
                  //
                  $("#" + father + " .mutarselect-rm" ).remove();
                  
                  $(this).parent(".mutarselect").hide();
                  $("<input type='text' placeholder='nuevo valor' autofocus autocomplete=off' class='mutarselect-input " + father +"' >").insertAfter( $($(this).parent(".mutarselect")) );
          });    
     
             
          $("form").on("keypress", ".mutarselect-input",function( event ){
              if ( event.keyCode == '13' ){
                  event.preventDefault();
  
                  $(this).prev(".mutarselect").prepend("<option selected=\"selected\" value='" + $(this).val()  + "' class='mutarselect-rm'>" + $(this).val() + "</option>");
                  $(this).prev(".mutarselect").show();
                  $(this).remove();
                  
              }
          });
  
          //return this;
  
      };
  }( jQuery ));