<?php
    $username = filter_input(INPUT_POST, 'username');
    $password = filter_input(INPUT_POST, 'username');

    if (!empty($username)){
    if (!empty($password)){
        $host ="localhost";
        $dbusername = "root";
        $dbpassword = "";
        $dbname = "field";

     $conn = new mysqli ($host, $dbusername, $dbpassword, $dbname);

     if (mysqli_connect_error()){
         die('ConnectError('.mysqli_connect_errno().')'
                 .mysqli_connect_error());
     }
     else{
         $sql = "INSERT INTO youtube(username, password)
             values ('$username','$password')";
         if ($conn->query($sql)){
             echo "new record inserted";
         }
         else "Error: ". $sql . "<br>". $conn->error;
     }
     $conn->close();
    }
        else{
            echo "Password should not be empty";
            die();
        }

    }
    else{
        echo "Username should not be empty";
        die();
    }
?>