Incorrect result

hi

i try to insert a text in a database (mysql)

in this text, there are php code i want to display... i use
<code>...</code> to do this job

str = $_POST['texttutoriel'];
$str = preg_replace_callback('`&lt;(code|url|img)&gt;(.+?)&lt;/\1&gt;`si',
'bbcode', htmlentities($str));
$str = mysql_real_escape_string($str)

my bbcode function:

function bbcode($m) {
switch($m[1]) {
case 'code' :
return '<div class="code"><pre>'.$m[2].'</pre></div>';
break;
//...
}
}


you can see the result here: http://www.laboiteaprog.com/tutoriel60-2

the part where i use <code> </code>... is ok, you can see it... the
rest of the text is not interpreted by the web navigator...

any idea

thanks
.