How to set the default location of 'tags table'?

How to set the default location of 'tags table'?

[Wu XiaoGuang]

Hi,all:
   When I press 'Alt-.' to find some-function's source,emacs will ask me 
to input the location(the default one is '~/').I must input 
'/usr/share/emacs/21.1/lisp'.
   How can I set the default location of 'tags table'?
   Thank you.

Re: How to set the default location of 'tags table'?

[Wu XiaoGuang]

Praveen D V wrote:
> Create a TAGS file using 'etags' and then U can give it
> directory name.  If U want to put it in U'r .emacs
> 
> (setq tags-table-list
>       '("~/abc" "/usr/share/"))
> 
> Hope this helps.
> regards,
> Praveen
> 
> 

I set it as:
    (setq tags-table-list '("/usr/share/emacs/21.1/lisp"))
It works now.
Thank you!