vi spaces and EMACS tabs -> conflicting

[TC Shen]

Hello all:
  I am new to CVS and this should be an easy question but I could not
find any answers in the old postings.

  My friends are using VI and place spaces in front of each line and I
am using EMACS and press TAB key to reformat his file.  When I do 'cvs
commit', nothing went wrong.  Then, my friends checked out and did 'cvs
co' then he got a lot of conflictings.  Is there any way we can tell CVS
to regard TAB the same as SPACE?

thank you

tc