I have set border='1' just so you can see tables location
when it all is alright and working
you can set border='0' if you want
top.htm is more often called 'header.php'
and bottom.htm called 'footer.php'
This is page.php
<body>
<table width='100%' border='1'>
<tr>
<td width='100%'><?php include 'top.htm'; ?></td>
</tr>
</table>
<table width='100%' border='1'>
<tr>
<td width='30%'><?php include 'side.htm'; ?></td><td width='70%'><?php include 'main.htm'; ?></td>
</tr>
</table>
<table width='100%' border='1'>
<tr>
<td width='100%'><?php include 'bottom.htm'; ?></td>
</tr>
</table>
</body>