EXHIBIT 5


Writer's Direct Phone:  (517) 371-8100

May 20, 2002


Commercial National
   Financial Corporation
101 North Pine River
Ithaca, MI 48847

Dear Gentlemen:

Re:      Commercial National Financial Corporation
         Registration Statement on Form S-3

You have requested our opinion as counsel to Commercial National Financial
Corporation, a Michigan corporation, in connection with a Registration Statement
filed with the Securities and Exchange Commission under the Securities Act of
1933, as amended, on Form S-3. The Registration Statement relates to an offering
by Commercial National Financial Corporation of its common stock to its
stockholders pursuant to the Commercial National Financial Corporation Dividend
Reinvestment Plan.

Based upon such examination and upon examination of such other instruments and
records as we deem necessary, we are of the opinion that:

1.       The Corporation has been duly incorporated under the laws of the State
         of Michigan, and is validly existing and in good standing under the
         laws of that state.

2.       The shares of common stock covered by this Registration Statement have
         been legally authorized; and when such shares have been duly delivered
         to stockholders against payment therefore as contemplated by the
         Commercial National Financial Corporation Dividend Reinvestment Plan,
         such shares will be legally issued, fully paid and nonassessable.

This opinion is furnished for use as an Exhibit to the Registration Statement.
We hereby consent to the filing of





this opinion as an Exhibit to the Registration Statement. We further consent to
the reference to this Firm under the caption "LEGAL MATTERS" in said
Registration Statement and related Prospectus.

FOSTER, SWIFT, COLLINS & SMITH, P.C.


/s/ Foster, Swift, Collins & Smith, P.C.