Exemplo de Tabuada

program tabuada;
uses crt;
var
   tab,vi,vf,i,r:integer;
   x:string[1];
   begin
   x:='s';
   while x='s' do
      begin
      textcolor(10);
      clrscr;
      writeln;
      write('Digite o numero da tabuada = ');
      readln(tab);
      write('Digite o valor inicial da tabuada = ');
      readln(vi);
      write('Digite o valor final da tabuada = ');
      readln(vf);
      writeln;
      for i:=vi to vf do
         begin
         r:=tab*i;
         writeln(tab,' X ',i,' = ',r);
         end;
      writeln;
      write('Deseja executar novamente? s/n = ');
      x:=readkey;
      writeln(x);
      if x='s' then
         begin
         writeln;
         write('Reiniciando...');
         delay(1000);
         end
      else
         begin
         writeln;
         write('Saindo do programa...');
         delay(1000);
         end;
      end;
   end.