want jQuery methods

my-jquery-extends.js

(function($) {
  $.extend({
    log: function(arg) {
      if (typeof console === 'undefined') {
        var ID = 'jquery-console-view',
            $console_view = $('#' + ID),
            $log = $('<p></p>').text(arg);
        if ($console_view.size() <= 0) {
          $console_view = $('<div></div>').attr({id: ID}).appendTo('body');
        }
        $console_view.append($log);
      } else {
        console.log(arg);
      }
    }
  });

  $.fn.extend({
    ch: function(expr) {
      return this.children(expr);
    }
  });
})(jQuery);