Hi Thanh
You will need to edit the code of the module alitle. Please look at the file modules/mod_edocman_documents/tmpl/default.php and try to edit it yourself. If you don't know how to edit, please submit a support ticket sending us FTP account of your site and we will be happy to edit it for you.
Sorry for slow on support. I was too busy in the last few days !
Regards,
Tuan