通过javascript提交表单时request.FILES为空

我试图在django中使用一个有文件的表单。表单如下所示，并放置在模态对话框的主体中

<form action="{%url 'customer-upload-xray' customer_id=customer_id%}" method="post" id="xrayform">
    {%csrf_token%}        
    <div class="form-group date">
        <label for="id_date">Date</label>
        <input class="form-control input-sm datepicker input-append date" id="id_date" name="date" readonly="" type="text">
    </div>
    <div class="form-group">
        <label for="id_type">Type</label>
        <select class="form-control input-sm" id="id_type" name="type">
            <option value="" selected="selected">---------</option>
            <option value="Observation">Observation</option>
            <option value="Initial">Initial</option>
            <option value="Progress">Progress</option>
            <option value="Final">Final</option>
            <option value="Post Treatment">Post Treatment</option>
        </select>
    </div>
    <div class="form-group">
        <label for="id_desc">Desc</label>
        <select class="form-control input-sm" id="id_desc" name="desc">
            <option value="PA Ceph">PA Ceph</option>
            <option value="Lateral Ceph">Lateral Ceph</option>
            <option value="Panoramic">Panoramic</option>
        </select>
    </div>
    <div class="form-group">
        <label for="id_image1">Image1</label>
        <input id="id_image1" name="image1" type="file">
    </div>
    <div class="form-group">
        <label for="id_image2">Image2</label>
        <input id="id_image2" name="image2" type="file">
    </div>
                    \
</form>

但是request.FILES是一个空的dict。发布时它怎么不在字典上传递文件呢

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编辑：在你想说的表格上加上一些enctype怎么样？？该死的我！！！如果主持人不想保留该问题，请删除该问题

我想说的是：enctype=multipart/form data

$("#upload").on('click', function(){
    form = $("#xrayform");
    form.submit();

});