{Search for and display lunar or solar eclipses}

{Clear the screen and put up a title}
display_title(+++ Lunar and solar eclipses +++)

{Which type of eclipse?}
set_string(s1,sun)
ask_for_string(Find eclipses of the Moon or Sun,s1)

{Carry out the calculation according to type}
if (s1=moon)
  display_title(*** LUNAR ECLIPSES ***)
  compute_eclipses(s1)
end_if

if (s1=sun)
  display_title(*** SOLAR ECLIPSES ***)
  compute_eclipses(s1)
end_if

{Check for an illegal entry}
if (s1!sun)
   if (s1!moon)
      set_normal_text(12)
      new_line
      write_string(+++ not an allowed value)
      new_line
      new_line
      set_normal_text(7)
   end_if
end_if

{Another go?}
ask_for_repeat