<PAGE>
Exhibit 5
[MAYS & VALENTINE, L.L.P. LETTERHEAD]
September __, 2000
Board of Directors
FNB Corporation
105 Arbor Drive
Christiansburg, Virginia 24068
Ladies and Gentlemen:
This letter is in reference to the Registration Statement on Form S-4 dated
September __, 2000, filed by FNB Corporation (the "Company") with the Securities
and Exchange Commission pursuant to the Securities Act of 1933, as amended (the
"Registration Statement"). The Registration Statement relates to 431,094 shares
of Common Stock, $5.00 par value per share (the "Shares"), which Shares are
proposed to be offered to the shareholders of SWVA Bancshares, Inc., a Virginia
bank holding company ("SWVA"), pursuant to an Agreement and Plan of Merger,
dated as of August 7, 2000, by and between SWVA and the Company, and
(collectively, the "Agreement").
We have examined such corporate proceedings, records and documents as we
considered necessary for the purposes of this opinion. We have relied upon
certificates of officers of the Company where we have deemed it necessary in
connection with our opinion.
Based upon such examination, it is our opinion that the aforementioned
Shares, when issued will be validly issued, fully paid and nonassessable under
the laws of the Commonwealth of Virginia.
We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to our firm under the caption "Legal
Opinion" in the Proxy Statement forming a part of the Registration Statement.
Very truly yours,
MAYS & VALENTINE, L.L.P.
