procedure ClearDBFIndexFlag(fn: string); // *.dbf
var ff:file;
bb:char;
begin
{$I-}
assignFile(ff, fn);
reset(ff,1);
seek(ff, 28);
bb:=#0;
blockwrite(ff, bb, 1);
blockwrite(ff, bb, 1);
close(ff);
fn := ChangeFileExt(fn, '.cdx');
if FileExists(fn) then Deletefile(fn);
fn := ChangeFileExt(fn, '.mdx');
if FileExists(fn) then Deletefile(fn);
{$I+}
end;