PRO sdss2txt, sdssspec, redshift=redshift, help=help

if (keyword_set(help)) then $ 
message, 'sdssDR9.fits redshift=redshift'
spec=mrdfits(sdssspec,1,h,/silent)
if keyword_set(redshift) then lam = (10.^(spec.loglam))/(1+redshift) $  
                         else begin 
                         lam=10.^(spec.loglam)  
                         print,'Warnning: Assuming deredshifted spectrum.'
                         endelse

spec2txt=STRMID(sdssspec,0,STRPOS(sdssspec,'.'))+'.txt'
openw, lun, spec2txt, /get_lun
for i=0, n_elements(lam)-1 do $
printf, lun, lam[i], (spec.flux)[i], (spec.ivar)[i], FORMAT='(3f10.4)'
free_lun, lun
close,lun 

END