Customizing chapter.titlepage

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" 
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<book>
	<title>Book Title</title>
	<chapter id="chapterone">
		<title>Chapter Title</title>
		<sect1 id="s1">
			<title>Section One Title</title>
			<para>
				Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
			</para>
		</sect1>
	</chapter>
</book>