program random_words;

uses
   crt;

const
   MAX_LETTERS    = 9;
   WORDS_PER_PAGE = 10;
   ESCAPE         = #27;

   alpha : array[1..26] of char =
  ('a','e','i','o','u','b','c','d','f','g','h','k','l',
   'm','n','p','r','s','t','j','q','v','w','x','y','z');

type
   wordtype = string[MAX_LETTERS];


procedure display_text;

begin
   gotoxy(34,7);
   textcolor(5);
   write('Random Words');

   textcolor(1);
   gotoxy(30,8);
   write('Press Escape to exit');

   textcolor(black);
end;


function random_limits(min,max : byte) : byte;

var
   rnd : byte;

begin
   repeat
      rnd := random(max+1);
   until rnd >= min;
   random_limits := rnd;
end;


procedure clrwin(x1,y1,x2,y2 : integer);

begin
   window(x1,y1,x2,y2);
   clrscr;
   window(1,1,80,25);
end;


procedure make_random_word(var word : wordtype);

var
   m,rnd,letter  : byte;
   no_of_letters : byte;

begin
   word := '';
   no_of_letters := random_limits(3,MAX_LETTERS);
   for m := 1 to no_of_letters do
   begin
      rnd := random_limits(1,20);
      case rnd of
         1..8   : letter := random_limits(1,5);
         9..17  : letter := random_limits(6,19);
         18..20 : letter := random_limits(20,26);
      end;
      word := word + alpha[letter];
   end;
end;


procedure display_word(word : wordtype;
                    var row : byte);

begin
   textcolor(3);
   gotoxy(36,row);
   write(word);
   inc(row,1);
   textcolor(black);
end;



var
   i,row : byte;
   word  : wordtype;
   pause : char;

begin
   textmode(80);
   randomize;

   display_text;

   while pause <> ESCAPE do
   begin
      clrwin(36,10,46,20);

      row := 10;
      for i := 1 to WORDS_PER_PAGE do
      begin
         make_random_word(word);
         display_word(word,row);
      end;

      pause := readkey;
   end;

   textcolor(lightgray);
   clrscr;
end.