finding tags files based on location

[gamename]

Hi,

I often have to checkout multiple copies of the same source tree from
cvs.  For example, if I have a source tree 'foo' in cvs, I may have 2
copies like ~/foo0/bar and ~/foo1/bar in my home directory at the same
time.  Each copy of the foo tree will have a tags file in 'foo/tags'.

Does anyone have code that will enable emacs to determine which tags
file to use based on the tree i'm currently using?  For example, if
I'm in foo1/bar, I would be using the tags file in foo1/tags, not foo0/
tags.  Is there code to dynamically determine that?

TIA,
-T