$html = Loader::helper('html');
if($u->isRegistered()) {
  $this->addHeaderItem($html->css('ccm.base.css'), 'CORE');
  $this->addHeaderItem($html->javascript('jquery.js'), 'CORE');
  $this->addHeaderItem($html->javascript('ccm.base.js'), 'CORE');
}
else {
  echo '<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>';
}

<script src="<?php echo $this->getThemePath(); ?>/css_browser_selector.js" type="text/javascript"></script>
<link rel="stylesheet" type="text/css" media="screen, projection" href="<?php echo $this->getStyleSheet('blueprint/screen.css'); ?>" />
<link rel="stylesheet" type="text/css" media="print" href="<?php echo $this->getStyleSheet('blueprint/print.css'); ?>" />
<!--[if IE]><link rel="stylesheet" type="text/css" media="print" href="<?php echo $this->getStyleSheet('blueprint/ie.css'); ?>" /><![endif]-->
<link rel="stylesheet" type="text/css" media="screen" href="<?php echo $this->getStyleSheet('main.css'); ?>" />
<link rel="stylesheet" type="text/css" media="screen"  href="<?php echo $this->getStyleSheet('typography.css'); ?>" />
<script type="text/javascript" src="<?php echo $this->getThemePath(); ?>/jQuery/jquery.dbPopWin.js"></script>