strip_tags doesn't work as expected.
When trying so trip <br>-tags, strip_tags doesn't strip anything. It maybe strips somewhere else, but not on my screen. :-)

Take this example code:
<?
$fin ="blabla<br>blabla";
$res =strip_tags($fin, "<br>");
echo $res;
?>

echo outputs blabla<br>blabla in the HTML-Source.

The solution is leaving the angle-brackets away like:
<?
$fin ="blabla<br>blabla";
$res =strip_tags($fin, "br");
echo $res;
?>

But this doesn't correspond with the Documentation at http://www.php.net/manual/en/function.strip-tags.php
Escaping with $res =strip_tags($fin, "\<br\>"); does it, but why?