Function FileSize(FileName : String) : Int64;
var
SearchRec : TSearchRec;
begin
if FindFirst(FileName, faAnyFile, SearchRec ) = 0 then // if found
Result := Int64(SearchRec.FindData.nFileSizeHigh) shl Int64(32) + // calculate the size
Int64(SearchREc.FindData.nFileSizeLow)
else
Result := 0;
end;