syntax error, unexpected 'elseif' (T_ELSEIF) on line 21 [duplicate]

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• PHP Parse/Syntax Errors; and How to solve them? 10 answers

I try attach to attach 2 files and both files have 2 separate upload buttons. when i try to upload, i receive error. this is my code with sql.

<?php

$membership_number = $_POST['membership_number'];

if(!is_null($_FILES['attach_id'])); {
$uploaddir = "uploads/$membership_number/id/";
    if (!is_dir($uploaddir)) {
        mkdir($uploaddir);
    }
$fileName = $membership_number.'_id.'. pathinfo($_FILES['attach_id']['name'], PATHINFO_EXTENSION);
$uploadfile = $uploaddir . $fileName;

move_uploaded_file($_FILES['attach_id']['tmp_name'], $uploadfile);
    $attach_id = $fileName;
}


elseif(!is_null($_FILES['attach_passport'])); {
$uploaddir = "uploads/$membership_number/passport/";
    if (!is_dir($uploaddir)) {
        mkdir($uploaddir);
    }
$fileName = $membership_number.'_passport.'. pathinfo($_FILES['attach_id']['name'], PATHINFO_EXTENSION);
$uploadfile = $uploaddir . $fileName;

move_uploaded_file($_FILES['attach_passport']['tmp_name'], $uploadfile);
    $attach_passport = $fileName;
}

$sql = "UPDATE attachments SET 
attach_id = '$attach_id',
passport = '$attach_passport' WHERE
membership_number = '$membership_number'";

if (!mysqli_query($conn, $sql)) {
    echo "Form Submission Failed:" .mysqli_error($conn);
} else {
     header("location: index.php");
}

mysqli_close($conn);

Line 21 is

elseif(!is_null($_FILES['attach_passport']));