Display a GUI window. The window need not have any contents, but should respond to requests to be closed.

$ include "seed7_05.s7i";
  include "draw.s7i";
  include "keybd.s7i";
 
const proc: main is func
  begin
    screen(200, 200);
    KEYBOARD := GRAPH_KEYBOARD;
    ignore(getc(KEYBOARD));
  end func;