how to implement function keys in linux programming
 

hello!

recently, I try to study program in linux. I have some problems. for example, I want to use a functional key F1, if I enter F1, end the program. else running others. However, in my program, when I enter 'F1', the program doesn't accord with what I expect to.
In my program, I use keypad function to respond to the control function, it seems that it doesn't work. To my acknowledge, I don't know why? now I list my program following:

/* =======================================*/
#include <ncurses.h>

WINDOW *create_newwin(int height, int width, int starty, int startx);
void destroy_win(WINDOW *local_win);

int main(int argc, char *argv[])
{ WINDOW *my_win;
int startx, starty, width, height;
int ch;

initscr();
cbreak();
keypad(stdscr, TRUE);

height = 3;
width = 10;
starty = (LINES - height) / 2;
startx = (COLS - width) / 2;
printw("Press F1 to exit");
refresh();
my_win = create_newwin(height, width, starty, startx);

while((ch = getch()) != KEY_F(1))
{ switch(ch)
{case KEY_LEFT:
destroy_win(my_win);
my_win = create_newwin(height, width, starty,--startx);
break;
case KEY_RIGHT:
destroy_win(my_win);
my_win = create_newwin(height, width, starty,++startx);
break;
case KEY_UP:
destroy_win(my_win);
my_win = create_newwin(height, width, --starty,startx);
break;
case KEY_DOWN:
destroy_win(my_win);
my_win = create_newwin(height, width, ++starty,startx);
break;
default:
break;
}
}

endwin();
return 0;
}

WINDOW *create_newwin(int height, int width, int starty, int startx)
{
WINDOW *local_win;
local_win = newwin(height, width, starty, startx);
box(local_win, 0 , 0);
wrefresh(local_win);
return local_win;
}

void destroy_win(WINDOW *local_win)
{
wborder(local_win, ' ', ' ', ' ',' ',' ',' ',' ',' ');
wrefresh(local_win);
delwin(local_win);
}
/*================================== */
in this program, when I enter FI,the program didn't stop, and return. unluckily, the same situation appear when I enter LEFT,RIGHT,UP,DOWN key,the program doesn't expect to my desire.

please give me some advice, thanks!

who can help me?