jQuery.fn.popup_window = function (options) {
  
  var defaults = {
    url: '',
    closeText: '',
    effect: 'blind'
  };
  options = jQuery.extend(defaults, options);
  
  return this.each(function(){
    jQuery(this).click(function(){
      var element = jQuery(this);
      
      var content = $.ajax({ url: options.url, type: 'get', async: false }).responseText;
      
      if (!element.next().hasClass('popup_window'))
      {
        element.after('<div class="popup_window"><div class="popup_window_close"><a href="javascript: void(0);">'+options.closeText+'</a></div><div class="popup_window_content">'+content+'</div></div>');
        
        element.next().find('*').filter('.popup_window_close a').click(function(){
          element.next().hide(options.effect);
        })
      }
      
      element.next().show(options.effect);
    });
  });
}