AJAX不会发送POST数据

Question

I'm currently working on a project which requires some AJAX, but for some reason my current code wont send the POST data. here is my AJAX:

<script>
$('#greenon').click(function(){

    $.ajax({
            type: 'POST',
            url: 'command.php', 
            data : { "green" : "on" },
            success: function(data, textStatus, jqXHR) {
                    alert("it worked!");
            },
            error: function(jqXHR, textStatus, errorThrown) {
                    alert("didn't work!");
            }
    });

    return false;
});
</script>

And it's not even sending the 'didnt work' alert. I am using this in command.php (it would write the file if command.php got accessed,

<?php
$content = "bleh";
$fp = fopen($_SERVER['DOCUMENT_ROOT'] . "/file.txt","wb");
fwrite($fp,$content);
fclose($fp);
?>

Why is it not sending POST data? thanks!

oh and here is my button HTML:

<a class="btn btn-success" role="button" id="greenon">Turn On</a>

Answer 1

It seems that your JS code is before your's button HTML code, so the binding doesn't work. Put your JS after <a>...</a>, or frame it with $(document).ready() callback:

<script>
    $(document).ready(function() {
    $('#greenon').click(function(){

    $.ajax({
            type: 'POST',
            url: 'command.php', 
            data : { "green" : "on" },
            success: function(data, textStatus, jqXHR) {
                    alert("it worked!");
            },
            error: function(jqXHR, textStatus, errorThrown) {
                    alert("didn't work!");
            }
    });

    return false;
});
});
</script>