百度文库里面有操作方式http://wenku.baidu.com/link?url=jpkuY7dWKReF_iKgOJxE6d6fUY0FVVLj5VTavsUyJsxSXo-5wdE1IaSDccPAwqIVXFD1-unKqqG2xBABnwFESN-6v60LXb0QZzaYfxOkG6q
