AJAX call doesn't call alerts

Question

I've got a button which triggers a function on click

<input type="button" value="Change Stuff" onClick="Change()" />

This is the said function :

function Change()
{
    var z = confirm("You are about to change something!");
    if (z){
    var value1 = prompt("Change Value1 : ");
    var value2 = prompt("Change Value2 : ");
    var value3 = prompt("Change Value3 : ");
    $.ajax({
            url: ('ajax-call.php'),
            type: 'POST',
            data: { 
            id: '<?php echo $_GET["id"]; ?>',
            value1: value1,
            value2: value2,
            value3: value3
            },
            dataType: 'script'
          });
    } else {
        return false;
    }
}

The data beeing called by AJAX

<?php
include "connect.php";

        $id = $_POST["id"];
        $value1 = $_POST["value1"];
        $value2 = $_POST["value2"];
        $value3 = $_POST["value3"];
        $currentDate = date("Y-m-d");

        $sql = $conn->query("UPDATE tbl_table1 SET datum='". $currentDate ."',value1='". $value1 ."', value2='". $value2 ."',value3='". $value3 ."',einstellung='". 2 ."' WHERE id =" . $id) or die('Error Updating table_1 - Error Message : ' .mysqli_error($conn));
        if ($conn->affected_rows == 0){
                echo '<script type="text/javascript"> alert(\'No data found!\'); </script>';
        } else {
                echo '<script type="text/javascript"> alert(\'Success!\'); </script>';
                $result = $conn->query("UPDATE tbl_table2 SET status='" . 1 ."' WHERE id =" . $id) or die('Status could not be set - Error Message : ' .mysqli_error($conn));
        }

        mysqli_free_result($sql);
        mysqli_free_result($result);
?>

Not sure if important but also in my code (reload to see ticked checkbox) :

$(document).ajaxStop(function(){
    location.reload(true);
});

My only problem is : the alerts never appear. I tried to reconstruct it on a test page with given variable values and not $_POST's and it alerted when I called the site directly.
I don't know much about AJAX and this is actually my first time working with it..So my question would
be, is AJAX blocking alert() or is there a mistake in my code?

The Main idea behind this was : Check if the id is in the table, if it is update some values and then inform that a match was found. Then update table2. Else just alert that the id is not in the table.

Answer 1

you should be use callbak function for ajax request. After that , According to response , In callback , you should call alert function

Answer 2

if u reload page that will reset ur page to default. u should use

ajax setting like that:

$.ajax({
        url: ('ajax-call.php'),
        type: 'POST',
        data: { 
        uid: '<?php echo $_GET["id"]; ?>',
        value1: value1,
        value2: value2,
        value3: value3
        },
        dataType: 'script',
        success: function(response){
           alert(response);
        }
      });

Answer 3

try like this

function Change()
{
    var z = confirm("You are about to change something!");
    if (z){
    var value1 = prompt("Change Value1 : ");
    var value2 = prompt("Change Value2 : ");
    var value3 = prompt("Change Value3 : ");
    $.ajax({
            url: ('ajax-call.php'),
            type: 'POST',
            data: { 
            id: '<?php echo $_GET["id"]; ?>',
            value1: value1,
            value2: value2,
            value3: value3
            },
            dataType: 'script'
          }).done(function (msg) {

            alert(  msg );
        }
        document.location = "cableList.php";
    });;
    } else {
        return false;
    }
}

PHP 
<?php
include "connect.php";

        $id = $_POST["id"];
        $value1 = $_POST["value1"];
        $value2 = $_POST["value2"];
        $value3 = $_POST["value3"];
        $currentDate = date("Y-m-d");

        $sql = $conn->query("UPDATE tbl_table1 SET datum='". $currentDate ."',value1='". $value1 ."', value2='". $value2 ."',value3='". $value3 ."',einstellung='". 2 ."' WHERE id =" . $id) or die('Error Updating table_1 - Error Message : ' .mysqli_error($conn));
        if ($conn->affected_rows == 0){
                echo 'No data found!';
        } else {
                echo 'Success';
                $result = $conn->query("UPDATE tbl_table2 SET status='" . 1 ."' WHERE id =" . $id) or die('Status couldn't be set - Error Message : ' .mysqli_error($conn));
        }

        mysqli_free_result($sql);
        mysqli_free_result($result);
?>