Drupal - write value to textarea with editor with js

foo.js

(function ($) {
  Drupal.fooModule = Drupal.enrich || {};
  Drupal.fooModule.copyToTextarea = function($field, $value, settings) {
    for (var editor in settings.wysiwyg.configs) break;
    $("textarea[name^='"+ $field +"']").val($.trim($value));
    var editorid = $("textarea[name^='"+ $field +"'].text-full").attr('id');

    if (typeof editorid != 'undefined' && editorid.length > 0) {
      if (editor == 'tinymce') {
          tinyMCE.execInstanceCommand(editorid, 'mceSetContent', false, $.trim(html));
      }
      else if (editor == 'ckeditor') {
          CKEDITOR.instances[editorid].setData($.trim(html));
      }
    }
  };
})(jQuery);