//ɾ����Ƭ�ļ�
int photo_id = Integer.parseInt(s_photo_id);
PhotoBean pbean = PhotoDAO.getPhotoByID(photo_id);
String ext = null;
if(pbean != null){
HttpContext context = getHttpContext(mapping, form, request, response);
getPhotoSaver().delete(context, pbean.getImageURL());
if(!pbean.getPreviewURL().equals(pbean.getImageURL()))
getPhotoSaver().delete(context, pbean.getPreviewURL());
//ɾ�����ݿ���Ϣ
PhotoDAO.delete(pbean);