pro rdimg,img
 on_error,1
 mtitle='AVAILABLE CHOICES'
 list=['FIS ','FTE','UVSP','QUIT']
 repeat begin                            ;data read loop
  ok=1
  option=emenu(list,init=1,mtitle=mtitle)+1
  case option of
   1: rdfis,img 
   2: rdfte,img
   3: get_uvsp,img
   4: message,'aborting...'
   else: begin
          print,'* try again please' & ok=0
         end
  endcase
 endrep until ok                                ;end data read loop
 return
 end