Wordpress Plugin - Embed Javascript into PHP Function

I am trying to create a Wordpress plugin by GCM service which is provided by Google.

I read quite a lot of article about creating web service as a plugins.

After doing some research and reading, I managed to created GCM Web Service.

It works like a charm.

<?php
    require ('gcm-web-service.php');

    add_action('admin_menu', 'gcm_push_javascript');
    add_action('wp_ajax_gcm_push', 'gcm_push_action');

    function gcm_push_javascript() {
?>
    https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js
    
    jQuery(document).ready(function($) {
        $("#push-promotion").click(function() {

            $(this).find(".spinner").addClass("is-active");

            var id = $(this).data("id");

            var data = {
                'action': 'gcm_push',
                'post_id': id
            };


            $.ajax({
                type: "POST",
                url: ajaxurl,
                data: data,
                success: function(response) {

                    $(".publish-to-phone #publishing-action .spinner").addClass('is-active');
                }
            }).done(function() {
                $(".publish-to-phone #publishing-action .spinner").removeClass('is-active');

                $('
Promotion had been pushed to mobile successfully.
').prependTo('body');

                $n = $('#notification'),
                nHeight = $n.outerHeight();

                showNotification();
                setTimeout(hideNotification,8000);

                function showNotification() {
                    $n.css('top',-nHeight).addClass('anim').css('top', 0);
                }

                function hideNotification() {
                    $n.css('top',-nHeight);
                    setTimeout(function() { $n.removeClass('anim'); }, 1000);
                }
            });
        });
    });

<?php
}

As you can see, I had embedded Javascript into PHP Function.

But problem occurred when I'm trying to upload an image.

Please referred to the image below.

The problem was solved once I removed the function above.

After that, I tried to inspect the error by using Firebug and it showed nothing.