Error Index undefined when i try send from android to mysql database

So currently i made menu to send a data from android to mysql database, but when i press send button that error always come,
here is my php code(addKomen.php)


    //Getting values
    $nama = $_POST['nama'];
    $email = $_POST['email'];
    $isi = $_POST['isi'];

    //Creating an sql query
    $sql = "INSERT INTO email (nama,email,isi) VALUES ('$nama','$email','$isi')";

    //Importing our db connection script

    //Executing query to database
        echo 'Added Successfully';
        echo 'Could Not Add';

    //Closing the database 


So the problem is in my android code, because i type different variable
thanks for all the answer and then the problem is in my android code.
Best regards

You are not posting the data correctly, and to resolve the undefined index: nama use isset() to check whether the index you are trying to get is exist or not like:

if( isset( $_POST['nama'] ) )
    // This block will execute only if nama have some value in it.