CursorUp(screen, n) register TScreen	*screen; int		n;
CursorUp(register TScreen *screen, int n)
CursorUp(screen, n)register TScreen	*screen;int		n;{	register int min;	min = (screen->cur_row < screen->top_marg ?		0 : screen->top_marg);	screen->cur_row -= n;	if (screen->cur_row < min)		screen->cur_row = min;	screen->do_wrap = 0;	_CheckSelection(screen);}