path reference issue with a single masterpage and subfolders on a - markm7

There is probably some simple answer to my question, but i'm still new to
this a bit..

I have a master page.. with a menu system which is coded onto the
masterpage.aspx... it uses A tags with hrefs etc.. the usual stuff..

I also have a sub section on the site.. where aspx files arent in the
root.. ie:   /rootfiles.aspx here.. then /subsection/subfiles.aspx

The menu is fine and dandy with the usual relative references like <a
href="default.aspx" > for the root page.. but when you are say
/subsection/subfiles.aspx all the menu items paths are incorrect.

So at this point i figure i have two or 3 choices.. I could one, make a
seperate masterpage in the subsection (not desired).. or.. I can just do a
search in the request.path variable for the word "subsection" and if it
exists, then dynamically change all the menu items href paths to the correct
format.. ie:  if in a subsection, href becomes ./default.aspx for the root
page..

In doing this second option, it seems i have to do the same thing on the
masterpage.aspx.. as there is a  reference in there and
this cant be changed, only on the aspx file itself (ie:  i cant reference it
in codebehind in the page load event).

Any thoughts on this?  If these options are the best ones.. would it be a
bad idea to make all the menu links runat="server", so that i can access the
href property from the page load event and set all the values in that
procedure.. or would i be just as good to do all the checks in the embedded
c# code in the aspx page itself.. albeit a bit more messy but all client side?

Thanks