#This routine takes a flat-fielded image (Fy...), and multiplies by
#The sky correction image. Eventually there should be a series of these
#which also takes into account exposure time... 
#task y4ksky=/home/massey/survey/y4ksky.cl
procedure y4ksky(img)
    string img {prompt="sky correction image"}
begin
     string sky
#Get parameter
       sky=img
delete("objs")
hselect("%F%%y*.fits","$I","imgtype='OBJECT'",>"objs")
imdelete("S"//"@objs")
imarith ("F"//"@objs","/",sky,"S"//"@objs")
end