function readlayr, mygrd, filename

; see mklev.pro to create the layers this code reads

; Jan 2010
; read a 'station.layers' file for the retrieval alt grids
;filename = 'station.layers'

print, '   readlyr 1 : stations file : ', filename

buf = ''
openr, lun, filename, /get_lun
readf, lun, buf
readf, lun, klay
readf, lun, buf
;print, buf
mygrd = {k          : klay,		      $
	      alts       : dblarr(klay),    $
	      thik       : dblarr(klay),    $
	      grth       : dblarr(klay),    $
	      midp       : dblarr(klay)     }

dat = dblarr(5,klay)
readf, lun, dat
free_lun, lun

mygrd.alts = reverse(dat[1,*],2)
mygrd.thik = reverse(dat[2,*],2)
mygrd.grth = reverse(dat[3,*],2)
mygrd.midp = reverse(dat[4,*],2)

;print, mygrd.midp, format='(100f11.2)'

return, fix(klay) ; midpoints
end