Using AJAX to call PHP script

Using AJAX to call PHP script

Hello there. I am planning to use an AJAX call to a PHP script that accesses a REST servlet. My php script would be very simple; something like:

<?php
    // call the RESTlet to grab data from the database
    $output = file_get_contents('http://localhost:xxxx');
    echo $output;
?>

This is the code for my AJAX call:

$.ajax({
                        url: 'myscript.php',
                        dataType: 'json',
                        success: function(series)
                        {
                            // plot the data with Flot
                            plot = $.plot(placeholder, [series], options);
                        }
                    });

This is the error that Firefox's Error Console gives me:

"Error: no element found
Source File: file:///C:/workspace/Database/myscript.php
Line: 9, Column: 3
Source Code:
?>"

I'm an experienced programmer, but I'm fairly new to web development, so I am having trouble interpreting this error. What have I done wrong? Is this the proper way to call a PHP script with AJAX?