<script type="text/javascript">
    $(document).ready(function() {
        $("a").click(function() {

            var content = $('#content').html();

            var data = {"content":content};


            $.ajax({
                type: "POST",
                dataType: "json",
                url: "ajax.php",
                data: {content:content},
                success function (data) {
                    alert('Hello!');
                }

            });


        });

    });        
</script>

<div id="content"><?php echo $content; ?></div>

ajax.php

echo json_encode($_POST['content']); ?>

Nothing happens... WhatI really want to achieve is to get that alert box and get the return data, but I am lost since I don't get any errors or nothing.