使用参数从JavaScript调用PHP脚本

I have done a lot of research on Google and StackOverflow but I can't solve this problem (that's why this question is no duplicate): I have a js function, which is called on click (working). With this function I'm trying to call a PHP script to execute... But it doesn't react... Please tell me what's wrong (complete solution would be appreciated...)

PHP code:

<?php
$servername = "bot-sam.lima-db.de:3306";
$username = "USER379138";
$password = "pwd";
$dbname = "db_379138_1";

$q = $_POST['q'];
$a = $_POST['a'];

function alert($msg) {
    echo "<script type='text/javascript'>alert('$msg');</script>";
}

echo $q . $a;
// echo and alert are not opening so i think the php script isn't executing
alert("question is " . $q);
alert("answer is " . $a);

// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

$sql = "INSERT INTO knowledge_base ('question', 'answer')
VALUES ($q, $a)";

if (mysqli_query($conn, $sql)) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}
mysqli_close($conn);
?>

JavaScript function (which gets called properly; jQuery working):

function myfunc() {
    var question = "test1";
    var answer = "test2";
    $.ajax({
        url: 'phpscript.php',
        type: 'POST',
        data: {q: question, a: answer},
        dataType: 'json',
        sucess: console.log("SQL entry made")
    });
}

I'm sorry to ask such a simple question but I just can't solve the problem...

Try to use the below code

function myfunc() {
    var question = "test1";
    var answer = "test2";
    $.ajax({
        url: 'phpscript.php',
        type: 'POST',
        data: {q: question, a: answer},
        dataType: 'json',
        success: function(result) {
         console.log(result);
       }
    });
}