register.php for help

//Get all POST data from user trying to register
$username = $_POST['username'];
$password =  $_POST['password'];
$name = $_POST['name'];
$email = $_POST['email'];
$lat = $_POST['lat'];
$lon = $_POST['lon'];

//Choose wether the user will be "it" or "not it"
$choose_it = array('it', 'not it');
$key = array_rand($choose_it);
$it = $choose_it[$key];

$message = "";

$allEmails = "";
$allUnames = "";

function strong_crypt($input, $rounds = 81)
{
    $salt = "";
    $salt_chars = array_merge(range('A','Z'), range('a','z'), range(0,9));

    for($i=0; $i < 22; $i++)
    {
        $salt .= $salt_chars[array_rand($salt_chars)];
    }
    return crypt($input, sprintf('$2a$%02d$', $rounds) . $salt);
}

//Get emails from registered users and check if it has already been used
$AllPeople = "SELECT email, uname FROM login WHERE email = '$email'";
$query = mysqli_query($conn,$AllPeople);

while($row = mysqli_fetch_array($query))
{
    $allEmails = $row['email'];
    $allUnames = $row['uname'];
}

if($allEmails != "")
{
    $message = "That email already exists. You can only have one account per email address.";
}

if($allUnames != "")
{
    $message = "That username has already been taken. Please choose a different one.";
}

if($allEmails === "" && $allUnames === "")
{
    $hash = strong_crypt($password);

    mysqli_query($conn, "INSERT INTO login (name, uname, pword, email, lat, lon, it) VALUES ('$name', '$username', '$hash', '$email', '$lat', '$lon', '$it')");

    $message = "goodtogo";
}

echo json_encode(array("message" => $message, "name" => $name, "it" => $it));

mysqli_close($conn);