uses Windows;

procedure ClrScr;
var
  S: String;
  H: DWORD;
  Coord: _COORD;
begin
  H := GetStdHandle(STD_OUTPUT_HANDLE);
  Coord.X := 0;
  Coord.Y := 0;
  SetConsoleCursorPosition(H, Coord);
  S := StringOfChar(Chr(32), 2000);
  WriteLn(S);
  SetConsoleCursorPosition(H, Coord);
end;