Org mode set table of contents level

• http://orgmode.org/org.html
  

search toc in the page, and locates:

toc:
     Toggle inclusion of the table of contents, or set the level limit
     (org-export-with-toc)
              

If the paper has 5 levels of headings, the table of contents will also show
5 levels of headings.

It's ugly, we only need 2 levels in the table of contents.

keep the code below to you .emacs, and then restart emacs. Try to export your
org-mode document again, you will get what you want.

(setq org-export-with-toc 2)