AJAX请求保存到数据库但警报失败

I have a bootstrap modal contact form which uses AJAX and PHP to save the information sent by a user to a database:

        <div class="modal fade" id="contact" role="dialogue">
    <div class="modal-dialog">
        <div class="modal-content">

            <div class="modal-body">
                <form id="myform" role="form">

                    <div class="form-group">

                        <label for="name">Name: </label>
                        <input type="name" name="name" class="form-control" id="name" >

                    </div>

                    <div class="form-group">

                        <label for="email">Email: </label>
                        <input type="email" name="email" class="form-control" id="email">

                    </div>

                    <div class="form-group">

                        <label for="msg">Message: </label>
                        <textarea class="form-control" name="msg" id="msg" rows="10"></textarea>
                    </div>

                    <!-- <a class="btn btn-primary" data-dismiss="modal">Close</a> -->
                    <button id="sub" type="submit" name="submit" class="btn btn-default">Submit</button>

                </form>
            </div>
        </div>
    </div>
</div>

When I submit the form the page alerts that the AJAX request has failed but yet the information still saves to the database!? anybody know where I'm going wrong, I have attached my script.js and send.php file below:

Javascript/Ajax file:

$(document).ready(function(){
$('#myform').submit(function(){

    $.ajax({
        type: 'post',
        url: 'send.php',
        dataType: 'json',
        async: true,
        data: $('#myform').serialize(),
        success: function(msg){
            alert("It was a success");
            return false;

        },
        error: function(jqXHR, textStatus, errorThrown){
            alert("Fail");
            console.log(jqXHR + '-' + textStatus + '-' + errorThrown);
            return false;
        }
    });
});
});

PHP file for processing and saving to DB

<?php

include 'connect.php';

if(isset($_POST['name'])&&($_POST['email'])&&($_POST['msg']))
{
$sql = "INSERT INTO details (name, email, message) VALUES (:Name, :Email, :Msg)";

$stmt = $pdo->prepare($sql);

$stmt->bindParam(':Name', $_POST['name'], PDO::PARAM_STR);
$stmt->bindParam(':Email', $_POST['email'], PDO::PARAM_STR);
$stmt->bindParam(':Msg', $_POST['msg'], PDO::PARAM_STR);

$stmt->execute();

echo "done";

}else{

echo "Nothing posted";

}

?>

P.S No errors are output to the console, just the alert saying failed.

As Luis suggests, try to add proper header to the php file which saves to the database and make the output json object like so:

<?php

include 'connect.php';

//The json header
header('Content-type: application/json');
header("Content-Disposition: inline; filename=ajax.json");

if(isset($_POST['name'])&&($_POST['email'])&&($_POST['msg']))
{
    $sql = "INSERT INTO details (name, email, message) VALUES (:Name, :Email, :Msg)";

    $stmt = $pdo->prepare($sql);
    $stmt->bindParam(':Name', $_POST['name'], PDO::PARAM_STR);
    $stmt->bindParam(':Email', $_POST['email'], PDO::PARAM_STR);
    $stmt->bindParam(':Msg', $_POST['msg'], PDO::PARAM_STR);

    $stmt->execute();

    $result = array('success'=>true, 'message'=>'The data has been saved successfuly');

} else {
    $result = array('success'=>false, 'message'=>'Can\'t save the data');
}

//Also is a good practice to omit the php closing tag in order to prevent empty characters which could break the posted headers

echo json_encode($result);

I would use the following alias instead of $.ajax, but it's a personal preference:

$(document).ready(function(){
   $('#myform').submit(function(e){
       e.preventDefault(); //Prevent form submission, so the page doesn't refresh
       $.post('send.php', $(this).serialize(), function(response){
           console.log(response); //see what is in the response in the dev console
           if(response.success == true){
               //success action
               //...some code here...
           } else {
               //error action, display the message
               alert(response.message);
           }
       });
   });
});

Hope that helps

according to your javascript, your ajax is expecting to receive a json result, look at this line

 dataType: 'json',

but in your php code you are only echoing a string

 echo "Nothing posted";

two solutions , delete this code in your javascript dataType: 'json' or return a json in your php

 $data['result'] = "nothing posted";
 echo json_encode($data);