помогите с шаблонами

<?php
echo <<<DATA
<table>
<tr>
<td>
<a href="?mode=main"><img src="home1.gif"></a>
<a href="?mode=news"><img src="news1.gif"></a>
<a href="?mode=about"><img src="about1.gif"></a>
<a href="?mode=serv"><img src="serv1.gif"></a>
</td>
</tr>
<tr>
<td>
DATA;
if(isset($_GET['mode'])){
switch($_GET['mode']){
case 'serv':include('serv.htm');
break;
case 'news':include('news.htm');
break;
case 'main':include('main.htm');
break;
case 'about':include('about.htm');
break;
}
}
else{
include('main.htm');
}
echo <<<DATA
</td>
</tr>
</tr>
</table>
DATA;
?>