function extract_NCEP(NCEP_dir,url,fname,vname,year,month,...
                      lon,lat,tndx,time,...
                      trange,level,jrange,...
                      i1min,i1max,i2min,i2max,i3min,i3max,...
                      jmin,jmax,Yorig,Get_My_Data)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Extract a subset from NCEP using OPENDAP if Get_My_Data~=1 
% Extract a subset from NCEP my ftp data   if Get_My_Data==1
%
% Write it in a local file
% 
%
%  Further Information:  
%  http://www.croco-ocean.org
%  
%  This file is part of CROCOTOOLS
%
%  CROCOTOOLS is free software; you can redistribute it and/or modify
%  it under the terms of the GNU General Public License as published
%  by the Free Software Foundation; either version 2 of the License,
%  or (at your option) any later version.
%
%  CROCOTOOLS is distributed in the hope that it will be useful, but
%  WITHOUT ANY WARRANTY; without even the implied warranty of
%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%  GNU General Public License for more details.
%
%  You should have received a copy of the GNU General Public License
%  along with this program; if not, write to the Free Software
%  Foundation, Inc., 59 Temple Place, Suite 330, Boston,
%  MA  02111-1307  USA
%
%  Copyright (c) 2005-2006 by Pierrick Penven 
%  e-mail:Pierrick.Penven@ird.fr  
%
%  Updated    6-Sep-2006 by Pierrick Penven
%  Updated    22-Sep-2006 by Pierrick Penven (readattribute)
%  Updated    Jul-2007 to use Nomads3 server, J. Lefevre. 
%  Updated    Oct-2009 Gildas Cambon 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
check_time=1;
%
% Get the variable name
%
disp(['Get ',vname,' for year ',num2str(year),...
      ' - month ',num2str(month)])
%
% Get the variable 2D subset (take care of greenwitch)
%
if Get_My_Data~=1
  var=getdap(url,fname,vname,...
		 trange,level,jrange,...
		 i1min,i1max,i2min,i2max,i3min,i3max);	
%		 
  if check_time==1
    time_check=readdap([url,fname],'time',trange);
    startime = [1,1,1,0,0,0]; 
    TIME_OFFSET=(mjd(Yorig,1,1,0)-mjd(startime(1),startime(2),startime(3), ...
	  			  startime(4)));
    time_check = time_check - TIME_OFFSET -2;
    disp(datestr(time_check(1)+datenum(Yorig,1,1)))
    disp(datestr(time(1)+datenum(Yorig,1,1)))
    disp(datestr(time_check(end)+datenum(Yorig,1,1)))
    disp(datestr(time(end)+datenum(Yorig,1,1)))
  end
  %
  % Get the dataset attributes
  %
  x=readattribute([url,fname]);
  eval(['missing_value=x.',vname,'.missing_value;']);
else %if Get_My_Data
  nc=netcdf([url,fname,'.',num2str(year),'.nc']);
  numdimvar0=ncsize(nc{vname});
  numdimvar=length(numdimvar0);
  if ~isempty(i1min)
    if ( numdimvar > 3 )
      var1=squeeze(nc{vname}(tndx,1,jmin:jmax,i1min:i1max));
    else
      var1=squeeze(nc{vname}(tndx,jmin:jmax,i1min:i1max));
    end
  else
    var1=[];
  end
  %
  if ~isempty(i2min)
    if ( numdimvar > 3 )
      var2=squeeze(nc{vname}(tndx,1,jmin:jmax,i2min:i2max));
    else
      var2=squeeze(nc{vname}(tndx,jmin:jmax,i2min:i2max));
    end
  else
    var2=[];
  end
  %  
  if ~isempty(i3min)
    if ( numdimvar > 3 )
      var3=squeeze(nc{vname}(tndx,1,jmin:jmax,i3min:i3max));  
    else
      var3=squeeze(nc{vname}(tndx,jmin:jmax,i3min:i3max));    
    end
  else
    var3=[];
  end
  %
  var=cat(3,var1,var2,var3);
  close(nc)
  %
  nc=netcdf([url,fname,'.',num2str(year),'.nc']);
  add_offset=nc{vname}.add_offset(:);
  if isempty(add_offset)
    add_offset=0;    
  end
  scale_factor=nc{vname}.scale_factor(:);
  if isempty(scale_factor)
    scale_factor=1
  end
  missing_value=nc{vname}.missing_value(:);
  if isempty(missing_value)
    missing_value=-99999;
  end
  close(nc)
  %
end  %if Get_My_Data

%
% Correct the variable
%
if Get_My_Data~=1
  disp(['Get_My_Data is OFF'])
  var=shiftdim(var,2);
  var(var==missing_value)=NaN;
else
  disp(['Get_My_Data is ON'])
  var(var==missing_value)=NaN;
  var=add_offset+var.*scale_factor;
end  %if Get_My_Data

%
% Write it in a file
%
write_NCEP([NCEP_dir,vname,'_Y',num2str(year),'M',num2str(month),'.nc'],...
	   vname,lon,lat,time,var,Yorig)
%

return