我使用的是bootstrap模式的ckeditor， AJAX 调用后应该动态加载ckeditor中的数据，我无法加载ckeditor中的数据。代码：

<div class="modal fade" id="exampleModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
            <h4 class="modal-title" id="exampleModalLabel">Thank you Message</h4>
          </div>
          <div class="modal-body">
            <form>
              <div class="form-group">
                <label for="recipient-name" class="control-label">Recipient:</label>
                <input type="text" class="form-control" id="recipient-name">
              </div>
              <div class="form-group">
                <label for="recipient-name" class="control-label">Subject:</label>
                <input type="text" class="form-control" id="subject">
              </div>
              <div class="form-group">
                <label for="message-text" class="control-label">Message:</label>
                <?php $ckeditor->editor('message', '', array('id'=>'editor1')); ?>
              </div>
            </form>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
            <button type="button" class="btn btn-primary">Send message</button>
          </div>
        </div>
      </div>
    </div>

脚本

$(document).on('click', '#sendemail', function(){
    var target = $('#hidden_send_email_url').val();
    var id = $(this).find('#hidden_id').val();
    $.ajax({
        url : target,
        data : {id : id},
        type : 'POST',
        dataType: "json",
        success : function(data){
            var modal = $('#exampleModal').modal('show');
            modal.find('.modal-body input#recipient-name').val(data.to)
            modal.find('.modal-body input#subject').val(data.subject)
            CKEDITOR.instances.editor1.setData(data.message)
            
            
        },
        error : function(){
            alert('Error occured');
        }
    })
})

错误是：未捕获的类型错误：无法读取未定义的属性“setData”如何解决这个问题？欢迎任何帮助/建议。谢谢。