function val = ncreadatt(filename,varname,attname)

ncid = netcdf_open(filename,'NC_NOWRITE');
varid = netcdf_inqVarID(ncid, varname);
[varname_,xtype,dimids,natts] = netcdf_inqVar(ncid,varid);
val = [];
found = 0;

for i = 0:natts-1
  if strcmp(netcdf_inqAttName(ncid,varid,i),attname)    
    val = netcdf_getAtt(ncid,varid,attname);
    found = 1;
    break
  end
end

netcdf_close(ncid);

if ~found
  error('netcdf:readAttrib','attribute not found');
end