why my javascript is not working after @section('content')

In my laravel 5.6 application I have image upload and preview system with javascript, this is my file,

                            <form method="POST" action="http://localhost:8000/laravel-crud-image-gallery/create" accept-charset="UTF-8" enctype="multipart/form-data"><input name="_token" type="hidden" value="1LLYc0D1spmVSFMboLDjGM9MR4O5APVwng7giejx">
                                <div class="form-group row required">
                <label for="description" class="col-form-label col-md-3 col-lg-2">Description</label>
                <div class="col-md-8">
                    <input class="form-control" autofocus placeholder="Description" name="description" type="text" id="description">

                </div> 
            </div>

                        <div class="form-group row">
                <label for="image" class="col-form-label col-md-3">Image</label>
                <div class="col-md-5">
                    <img id="preview"
                         src="http://localhost:8000/images/noimage.png"
                         height="200px" width="200px"/>
                    <input class="form-control" style="display:none" name="image" type="file" id="image">
                    <br/>
                    <a href="javascript:changeProfile();">Add Image</a> |
                    <a style="color: red" href="javascript:removeImage()">Remove</a>
                    <input type="hidden" style="display: none" value="0" name="remove" id="remove">
                </div>
            </div>
<div class="form-group row">
                <div class="col-md-3 col-lg-2"></div>
                <div class="col-md-4">
                    <a href="" class="btn btn-danger">
                        Back</a>
                    <button type="submit" class="btn
                btn-primary">Save</button>
                </div>
            </div>
            </form>
        </div>
    </div>
    @endsection

javascripts

<script>
        function changeProfile() {
            $('#image').click();
        }
        $('#image').change(function () {
            var imgPath = $(this)[0].value;
            var ext = imgPath.substring(imgPath.lastIndexOf('.') + 1).toLowerCase();
            if (ext == "gif" || ext == "png" || ext == "jpg" || ext == "jpeg")
                readURL(this);
            else
                alert("Please select image file (jpg, jpeg, png).")
        });
        function readURL(input) {
            if (input.files && input.files[0]) {
                var reader = new FileReader();
                reader.readAsDataURL(input.files[0]);
                reader.onload = function (e) {
                    $('#preview').attr('src', e.target.result);
                    $('#remove').val(0);
                }
            }
        }
        function removeImage() {
            $('#preview').attr('src', 'http://localhost:8000/images/noimage.png');
            $('#remove').val(1);
        }
    </script>

but after add @section('content') to my script my image upload preview is not working without @section('content') is is working. how can fix this problem?

via Chebli Mohamed