YMAX
#ifndef YMAX
#define SCREENMAX (YMAX - 1) /* Number of lines displayed */
#define SCREEN_SIZE (XMAX * YMAX) /* Size of I/O buffering */
int ymax = YMAX;
if (lastrow > YMAX(wnd))
if (lastrow < YMAX(wnd)) {
wmove(wnd, YMAX(wnd), 0); wdeleteln(wnd); /* XXX */