Take note of the Playorder number sequence:
Code:
<navMap>
<navPoint id="navpoint" playOrder="1"><navLabel><text>Chapter One</text></navLabel><content src="Chapter_One.xhtml"/></navPoint>
<navPoint id="navpoint-1" playOrder="2"><navLabel><text>Mi</text></navLabel><content src="Mi.xhtml"/></navPoint>
<navPoint id="navpoint-2" playOrder="3"><navLabel><text>Mimi</text></navLabel><content src="Mimi.xhtml"/></navPoint>
<navPoint id="navpoint-3" playOrder="4"><navLabel><text>Mimimi</text></navLabel><content src="Mimimi.xhtml"/></navPoint>
<navPoint id="navpoint-4" playOrder="5"><navLabel><text>Chapter Two</text></navLabel><content src="Contents.xhtml"/></navPoint>
<navPoint id="navpoint-1" playOrder="2"><navLabel><text>Mi-two</text></navLabel><content src="Mi.xhtml"/></navPoint>
<navPoint id="navpoint-2" playOrder="3"><navLabel><text>Mimi-two</text></navLabel><content src="Mimi.xhtml"/></navPoint>
<navPoint id="navpoint-3" playOrder="4"><navLabel><text>Mimimi</text></navLabel><content src="Mimimi.xhtml"/></navPoint>
</navMap>