ScrollSelection(screen, amount) register TScreen* screen; register int amount;
ScrollSelection(register TScreen* screen, register int amount)
ScrollSelection(screen, amount)register TScreen* screen;register int amount;{    register int minrow = -screen->savedlines - screen->topline;    register int maxrow = screen->max_row - screen->topline;    register int maxcol = screen->max_col;#define scroll_update_one(row, col) \    	row += amount; \	if (row < minrow) { \	    row = minrow; \	    col = 0; \	} \	if (row > maxrow) { \	    row = maxrow; \	    col = maxcol; \	}    scroll_update_one(startRRow, startRCol);    scroll_update_one(endRRow, endRCol);    scroll_update_one(startSRow, startSCol);    scroll_update_one(endSRow, endSCol);    scroll_update_one(rawRow, rawCol);    scroll_update_one(screen->startHRow, screen->startHCol);    scroll_update_one(screen->endHRow, screen->endHCol);    screen->startHCoord = Coordinate (screen->startHRow, screen->startHCol);    screen->endHCoord = Coordinate (screen->endHRow, screen->endHCol);}