strtolower wont do his job

From: Kristof Goossens (newsgroups_at_z-web.be)
Date: 12/23/03 

Date: Tue, 23 Dec 2003 21:15:21 +0100

Hi you guys,

in the following insert the strtolower wont put the chars in lowercase.
Any ideas what i'm doing wrong?

the code:

$qryInsRel = "INSERT INTO \"tblrelations\" (rid, vcfirstname,
vclastname, vccompany, vcfunction, nlangid, ngenderid, nuserid,
ntitleid, dtbirthdate, vcbankaccount, vcvatnr, vctraderegisternr)
VALUES(" . $relNextVal .", '" . $_POST["txtFirstName"] . "', '" .

        strtolower($_POST["txtLastName"])

. "', '" . $_POST["txtCompany"] . "', '" . $_POST["txtFunction"] . "',
'" . $_POST["txtLanguage"] . "', '" . $_POST["txtGender"] . "', '" .
$_COOKIE["cUserID"] . "', '" . $_POST["txtTitle"] . "', '" . $bday .
"', '" . $_POST["txtBankaccount"] . "', '" . $_POST["txtVATNr"] . "',
'" . $_POST["txtTradeRegNr"] . "')";

(btw i moved a bit from the layout of the code but the rest is exactly
what i have)

thx in advance,

kristof