function  [count, errmsg]= nano2write(filename, header, img)
%NANO2WRITE  Write the header and the image to a nanoscope 2 file.
%
%       [COUNT, ERRMSG] = NANO2WRITE(FILENAME, HEADER, IMAGE)
%
%       Return the number of elements successfully written.
%              and an error message if occour.
%
%       Before to write the file, the image is -90 degree
%    rotated and the bytes are flipped in order to be
%    compatible with the nanoscope.
%
%
%       Claudio  October 11, 1995.

%
% Copyright (c) 1995 by Claudio Rivetti and Mark Young
% claudio@alice.uoregon.edu,    mark@alice.uoregon.edu
%

global Original_NANO2_header

HEADER_SIZE_NS2 = 2048;


fp = fopen(filename, 'w');

if fp == -1
    errmsg='Can not create file';
    return;
end


img=rot90(img, -1);

h=Original_NANO2_header;
h=setparameter(h, 'num_samp', size(img,1));
h=setparameter(h, 'scan_sz', scansize(header));
h=setparameter(h, 'text', getparameter(header, 'Note',1));
h=strrep(h, ': ', ' = ');
h=strrep(h, [13 10 92], [13 10]);
h=h(3:length(h));
hlen=length(h);
if hlen > HEADER_SIZE_NS2
  h=h(1:HEADER_SIZE_NS2);
else
  h=[h zeros(1,HEADER_SIZE_NS2-hlen)]; 
end

count_header = fwrite(fp, h', 'char');
count_img    = fwrite(fp, img, 'short', 'vaxd');
em=ferror(fp, 'clear');
fclose(fp);

count = prod(size(h)) + prod(size(img));

if count ~= count_header + count_img
    errmsg=em;
end

return