I need to concatenate path string as follows, so I added the following lines to my `.emacs` file:

```
(setq org_base_path "~/smcho/time/")
(setq org-default-notes-file-path (concatenate 'string org_base_path "notes.org"))
(setq todo-file-path (concatenate 'string org_base_path "gtd.org"))
(setq journal-file-path (concatenate 'string org_base_path "journal.org"))
(setq today-file-path (concatenate 'string org_base_path "2010.org"))

```

When I do `C-h v` `today-file-path` `RET` to check, it has no variable assigned.

What's wrong with my code? Is there any other way to concatenate the path string?

EDIT
----

I found that the problem was caused by the wrong setup, the code actually works. Thanks for the answers which are better than my code.