1 EXHIBIT 23(a) CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference in the Registration Statement of Commercial National Financial Corporation on Form S-3, of our report dated February 4, 1999 on the consolidated financial statements of Commercial National Financial Corporation, which report is included in the 1998 Annual Report on Form 10-K of Commercial National Financial Corporation. CROWE, CHIZEK AND COMPANY LLP Crowe, Chizek and Company LLP South Bend, Indiana June 23, 1999