units = 'meters'
units = 'none'
units = 'degrees_east'
units = 'degrees'
units = 'degrees_north'
units = 'pascal'
ia = ILNBLNK(units)
err = NF_PUT_ATT_TEXT(fid, vid, 'units', ia, units)
character*(MAX_LEN_NAME) units, long_name, positive
units(i:i) = ' '