$sql = "CREATE USER '$mysqluser'@'%' IDENTIFIED BY '$mysqlpassword1';";
$sql.= "GRANT SELECT, INSERT, ALTER, UPDATE, DROP, DELETE, CREATE ON $databasename.* TO '$mysqluser'@'%' IDENTIFIED BY '$mysqlpassword1';";
$sql.= "INSERT INTO pma__users (username, usergroup) VALUES ('$mysqluser', 'General User');";
$sql.= "CREATE DATABASE $databasename";
if (mysqli_multi_query($conn,$sql)) {
    echo 'Success.';
} else {
    echo 'Error.';
}

$conn->select_db("StartableHosting");
$sql2= "INSERT INTO mysql_accounts (username, cust_id) VALUES ('$username', '" . $_SESSION['id'] . "')";

if ($conn->query($sql2)){
    echo 'Success.';
} else {
echo 'Error.';
}