模态仅适用于第一篇文章

Question

我正在创建一个编辑发布按钮，用户单击其中的按钮，然后弹出带有表单的模态以编辑表单。由于某些原因，只有第一篇文章上的按钮可以使用并打开模式。不知道我在做什么错，任何帮助将不胜感激。预先感谢。模态中的帖子形式用于测试。

home.php：

@if($posts)
                @foreach($posts as $post)
            <div class="card" style="margin-top: 20px">
                <div class="card-header">
                    <div>{{$post->user->name}}</div>
                    <div id="post-date">{{$post->created_at->diffForHumans()}}</div>
                </div>


                <div class="card-body">
                    <div>{{$post->body}}</div>
                    @if(!empty($post->photo_id ))
                        <img class="post-image"src="/images/{{ $post->photo->file }}" alt="">
                    @else
                        <img class="post-image" src="http://placehold.it/400x400" alt="">
                    @endif



                    <div class="card-footer">
                        <div>
                            <button class="btn-primary btn-sm" id="edit-post-btn">Edit Post</button>

                            <!-- The Modal -->
                            <div id="myModal" class="modal">

                                <!-- Modal content -->
                                <div class="modal-content">
                                    <span class="close">&times;</span>
                                    <form method="POST" enctype="multipart/form-data" action="{{ route('makePost')  }}">
                                        @csrf

                                        <div class="form-group row">
                                            <label for="body" class="col-md-4 col-form-label text-md-right">{{ __('Body') }}</label>
                                            <div class="col-md-6">
                                                <input id="body" type="text" class="form-control" name="body" value="{{ old('body') }}">
                                            </div>
                                        </div>

                                        <div class="form-group row">
                                            <label for="photo" class="col-md-4 col-form-label text-md-right">{{ __('Photo') }}</label>
                                            <div class="col-md-6">
                                                <input id="photo" type="file" class="form-control" name="photo_id" value="{{ old('photo') }}">
                                            </div>
                                        </div>

                                        <div class="form-group row mb-0">
                                            <div class="col-md-6 offset-md-4">
                                                <button type="submit" class="btn btn-primary">
                                                    {{ __('Submit Post') }}
                                                </button>
                                            </div>
                                        </div>
                                    </form>
                                </div>

                            </div>
                        </div>
                    </div>



                </div>
            </div>
                @endforeach
                @endif

JS文件：

// Get the modal
var modal = document.getElementById('myModal');

// Get the button that opens the modal
var btn = document.getElementById("edit-post-btn");

// Get the <span> element that closes the modal
var span = document.getElementsByClassName("close")[0];

// When the user clicks on the button, open the modal
btn.onclick = function() {
    modal.style.display = "block";
}

// When the user clicks on <span> (x), close the modal
span.onclick = function() {
    modal.style.display = "none";
}

// When the user clicks anywhere outside of the modal, close it
window.onclick = function(event) {
    if (event.target === modal) {
        modal.style.display = "none";
    }
}