Editor dosen't work!

HI! I have been installed fckeditor version 2.1.1 in PHP(with MYSQL) mode, but does'nt work!!!

this is the code:

include("FCKeditor/fckeditor.php") ;
<form method=post action=update_bio.php>
<p align="center"><font size="2" face="Verdana, Arial, Helvetica, sans-serif">Testo:
<br>

    <?php
$oFCKeditor = new FCKeditor('testo') ;
$oFCKeditor->BasePath = 'FCKeditor/';
$oFCKeditor->Value = $testo ;
$oFCKeditor->Width  = '790' ;
$oFCKeditor->Height = '400' ;
$oFCKeditor->Create() ;
?>

<br>
</font><font size="2" face="Verdana, Arial, Helvetica, sans-serif"><br>

    <input name=id type="hidden" value="<?php echo $id ?>">

<br>
<input type=submit value=Invia>
</font></p>
<p align="center"><font size="2" face="Verdana, Arial, Helvetica, sans-serif">
</font></p>
</form>

it start but the editor doesn't change the font style/size ect... it work's like a normal form...
anyone can help me???
thanks

p.s. i'm sorry for my english