`change resolution
PERFORM CHECKLIST FOR DISPLAY MODES

start:
do
  input "select a resolution(l for list of available ones)";c$

  if c$ = "q" then exit

  if c$ = "l"
  for i = 1 to checklist quantity()
     print checklist string$(i)
  next i

  text 100,100,"any key to continue..."
  suspend for key
  cls
  endif

  if asc(c$)> 48
    mode = asc(c$)-48
  if mode > checklist quantity() then goto start
    width = checklist value a(mode)
    height = checklist value b(mode)
    color = checklist value c(mode)
    set display mode width, height, color
  endif
loop