Export to Latex without \author{}

[Lei Zhe <lzhes43@gmail.com>]

Dear orgers,

I am trying to export a beamer from org-mode with my own \author
command defined.
But when I export, org-mode always generates another \author after my
\author, which destroys the author list.
I tried:
1. #+author:
2. #+bind: latex-export-with-author ""
3. move #+author before my author command.
But none of them did make it. The \author{} always appears in the
place after my author command!

Then I tried to filter using:
(defun delete-empty-author (contents backend info)
  (when (eq backend 'beamer)
  (replace-regexp-in-string "\\\\author{}" "" contents)))
(add-to-list 'org-export-filter-keyword-functions 'delete-empty-author)
(add-to-list 'org-export-filter-plain-text-functions 'delete-empty-author)
(add-to-list 'org-export-filter-comment-functions 'delete-empty-author)

But it seems like that none of the filter functions is right.
So how can i solve this kind of problem?

llcc