ORA-24374 error on this code

[tatjana]

$siteId =0;
$siteName = siteLookup;
$query = "SELECT SITE_ID FROM $sitesTable
WHERE SI_LOOKUP = '$siteName' ";
$curser = @OCIParse($connection, $query);
if ( ! $result = @OCIExecute($curser,OCI_DEFAULT)) {
$returnCode = 1007;
$err = OCIError($curser);
$errorMsg = $err["code"]." ".$err[ "message" ];
errlog ("Date $currentDate Message Could not complete execute of select site ido from $sitesTable, ErrorMsg $errorMs
g, Query $query\n");
}

    while (@OCIFetchInto ($curser, $values)){
            $siteId = sprintf("%4d",$values[0]);
    }

The code is virtually identical to a previous bit in the same script and I cannot understand what the problem is.
thanks in advance 😕