4.3 curses - how to discard "premature" input?

[Xinhua Wu]

For the following program, how can I discard any premature input typed in
before the "Press any character: " prompt appears?

------------
#include <curses.h>

main()
{
  int ch;

  initscr();
  crmode();
  addstr("Press any character: ");
sleep(3);
  refresh();
  ch = getch();
  printw("\n\n\nThe character entered was a '%c'.\n", ch);
  refresh();
  endwin();
}
-------------

"sleep(3)" is added just to illustrate the point.  In practice, one often
has to wait for a menu to come up, etc.  But during the waiting one might
inadvertently type something (or hit a return) which should be discarded.

Thanks in advance for any help/comments.

------
Xinhua Wu
xwu at cse.usc.edu