如何通过ajax从php中的表单始终如一地传输数据?

There are two files:

1) index.html

<form id="myForm">
<textarea rows="10" cols="45" name="field1"></textarea>
<input type="submit" value="Send">
</form>

<div id="content"></div>

<script>
        $(document).ready(function(){
            $('#myForm').submit(function(){
                var str = $(this).serialize();
                $.ajax({
                    type: "POST",
                    url: "test.php",
                    data: str,
                    success: function(html){
                        $("#content").html(html);
                   }
                });
                return false;
            });

        });
    </script>

2) test.php

<?php 
$field1 = $_POST['field1'];
echo "Hello, <b>".$field1."</b>!<br>";
echo "Time: " . date("H:i:s") . "<br/>" . "
";
sleep(5);
echo "Done";
?>

I send to form:

Masha Dasha Peter Sasha

These are a list , separated by .

How to consistently transfer data using the ajax, in the php file to the output that:

Hello, Masha
Time: 10:06:00
ok
Hello, Dasha
Time: 10:06:05
ok
Hello, Peter
Time: 10:06:10
ok
Hello, Sasha
Time: 10:06:15
ok

The data should appear on the page, gradually, in this case 5 seconds may receive a prize of a subsequent action after receiving echo "ok"; I suppose that the first of these to get into the js array, wherein the separator is , gradually feed php, pre-opening session.

Note: The option to give the array in php, its subsequent expansion and echo sending is not suitable, since a large volume of incoming data is a high load, which will increase the expectation and may cause an error, and the gradual release of information in html can be no question .

P.S. Sorry for my bad English