how to hide "?>" in the header.php file

For some reason the last part of this php file is displaying on the page. Namely = ?>

How can I hide it from displaying both on the page and within my print section of my css?

<title><?php
$values = get_post_custom( $post->ID );
$seo_title = isset( $values[‘seo_title’] ) ? esc_attr( $values[‘seo_title’][0] ) : ”;
$seo_desc = isset( $values[‘seo_desc’] ) ? esc_attr( $values[‘seo_desc’][0] ) : ”;
$seo_keywords = isset( $values[‘seo_keywords’] ) ? esc_attr( $values[‘seo_keywords’][0] ) : ”;
if($seo_title != null && $seo_title != ”) {
echo $seo_title . ‘</title>’;
} else {
echo bloginfo(“blogname”) . ‘ | ‘;
echo the_title() . ‘</title>’;
}
if($seo_desc != null && $seo_desc != ”) {
echo ‘<meta name=”description” content=”‘ . $seo_desc . ‘” />’;
}
if($seo_keywords != null && $seo_keywords != ”) {
echo ‘<meta name=”keywords” content=”‘ . $seo_keywords . ‘” />’;
} ?>